All credit goes to Head_fish at bonefishgamer.com and TheMessiahOmen on trueachievements for the layout. I take no credit for the creation of the below.
Design : Mithril Trowel
Level/Location : Bree
Cost To Craft : 2 Bricks
How to get : You will find this design in the Blacksmiths shop. You will need to unlock it as part of the story, then craft it for the man waiting at the entrance to the Prancing Pony Inn.
Design : Whistle Sword
Level/Location : Bree
Cost To Craft : 4 Bricks
How to get : Break open the Morgul padlock on the door beside the entrance to the Prancing Pony, in Bree.
Design : Mithril Rope
Level/Location : Amon Hen
Cost To Craft : 3 Bricks
How to get : When you are fighting Lurtz at the end of the level, you will be able to see the design being held by a statue that is next to him. You will need to send a small character through the hatch that is on the back wall, and try to collect it as fast as possible, before Lurtz throws you back down again.
Design : Mithril Top Hat
Level/Location : The Battle of Pelennor Fields
Cost To Craft : 3 Bricks
How to get : While you are fighting the Mumakil, there is a large open area for you to explore. Near the middle there are two Mithril rocks that you can blow up. The one on the right contains the design.
Design : Mithril Stud Mallet
Level/Location : The Dead Marshes
Cost To Craft : 8 Bricks
How to get : As you near the end of the marshes, Sam will need to grow a large pink flower so you can jump up to a higher piece of land where Gollum waits for you. To the left of this flower, on the lower level, there is a padlock which you must find the key for. Walk towards the screen to find a fishing pier on the right side. Fish the key out, then unlock the padlock to get the design.
Design : Mithril Fishing Rod
Level/Location : Track Hobbits
Cost To Craft : 3 Bricks
How to get : When you reach the forest, go down the path a short distance, until you find an orange handle. Have a strong character pull it and go through the space behind it, into a cave. Inside the cave, walk towards the screen and you will find a small, brown chest on the right. Hit it a couple of times and the design will pop out.
Design : Mithril Music Boots
Level/Location : Weathertop
Cost To Craft : 3 Bricks
How to get : After you have completed breakfast, you will go off to a new area of the level. To the left of the save point, there is a dark doorway. Light it up and head inside to find the design.
Design : Mithril Climbing Boots
Level/Location : Mount Doom
Cost To Craft : 8 Bricks
How to get : As you progress up the hill, you will be able to build some brightly coloured bricks into stairs, by hitting the target to knock them down. When you have done that, climb the stair to reach a slightly higher part of the level and follow it round to the right. Continue past the orange handle on the crate and follow the wall to the right until you find the opening into the mountain. To the left of the gate there is an arrow hole which you can use to jump up and get the design that is floating next to it.
Design : Mithril Carrot Bow
Level/Location : Taming Gollum
Cost To Craft : 3 Bricks
How to get : At the start of the level, you will work your way up a slope to a tower. When you reach the base of the tower, you will be able to see two arrow holes on the right side of it. Put arrows into the holes then use it to make your way up to a dark recess. Light it up and you will find the design.
Design : Mithril Music Horn
Level/Location : The Black Rider
Cost To Craft : 3 Bricks
How to get : After defeating Saruman, continue along the path until you come to the river (before the bee hive). Head up the river until you find two rope hooks. Pull the one on the left to get the design.
Design : Mithril Shield
Level/Location : The Paths of the Dead
Cost To Craft : 3 Bricks
How to get : Through the level you will work your way along a tunnel with many rooms. To enter one of these rooms you will need to smash a wall down by getting Gimli to hit a cracked brick in the wall. Standing in the entrance to this room you will be able to see the design floating up on the left. This one can be a pain to get. You can walk up the wall on the left and get close to the design, but you cannot reach it, nor jump to it from this wall. However, while walking on the wall you will walk behind a bit of rock that sticks up slightly higher than the bit you are already stood on. Jump onto that and you will then be able to jump to the design.
Design : Mithril Tinderbox
Level/Location : The Black Gate
Cost To Craft : 8 Bricks
How to get : When you face the second troll, you will be on the right side of the gate. Right at the back, tucked away by the gate itself, there is a rope hook on a pile of bricks. Pull the rocks out of the way and beyond them is a spot to light a fire. Ignore that for now and walk behind the rock on the left to find the design.
Design : Mithril Headdress
Level/Location : The Mines of Moria
Cost To Craft : 3 Bricks
How to get : When you have gotten Pippin out of the well, you will need to start barricading the door. At this point, walk to the right and you may see a glow coming form the wall. There is a small space there that you can walk into to find the design.
Design : Mithril Gloves
Level/Location : Warg Attack
Cost To Craft : 4 Bricks
How to get : When fighting the Wargs, walk to the edge of the cliff and, somewhere near the middle, you will find a spot for Sam to plant a seed. When he has grown the plant, a vine will hang down over the edge of the cliff. Slide down it and, while hanging onto the vine, shoot the three targets on the cliff wall. You can then jump over and grab the rail, and work your way over to the right to collect the design.
Design : Mithril Shockwave Axe
Level/Location : Prologue
Cost To Craft : 4 Bricks
How to get : After defeating Sauron, you will find yourself on the slopes of Mount Doom. From the start of this area, you will see a cracked wall that will reveal a cave when broken open by Gimli. Inside the cave, go to the right and you will see that part of the wall is made of Lego bricks. Break them open and walk into the niche you uncovered, to find the design.
Design : Mithril Fire Bow
Level/Location : Helm’s Deep
Cost To Craft : 8 Bricks
How to get : After the Deeping Wall has been broken, you will need to make your escape by going up onto the left side of the wall. when you are past the rocks blocking your path, you will see a Mithril crate. Blow it up and the design is inside.
Design : Mithril Boxing Gloves
Level/Location : Osgiliath
Cost To Craft : 4 Bricks
How to get : Continue through the level until you have climbed your first Gollum wall. From there head down the stairs on the right and look to find the dark area underneath them. Have a character light this up and you can go in to get the design.
Design : Mithril Squeak Sword
Level/Location : The Secret Stairs
Cost To Craft : 4 Bricks
How to get : When you reach Shelobs lair, walk forward into a small cavern. On the left of this cavern there is a short tunnel running up on the left side. Go into the tunnel and destroy the web that is blocking your path. Continue along the passage destroying as you go, until you reach the end and find the design.
Design : Mithril Ice Bow
Level/Location : Cirith Ungol
Cost To Craft : 8 Bricks
How to get : While you are trying to rustle up some orc armour for your disguise, you will need to push a wooden platform along, past three boarded up niches. In the first niche you will find the design.
Design : Mithril Cluster Bow
Level/Location : The Pass of Caradhras
Cost To Craft : 4 Bricks
How to get : While you can hear Sarumans voice, you will need to send Gimli through a small character hatch, followed by Sam. Gimli will break a broken rock on the floor, then Sam must dig up some pieces of Lego. Build these into a long plank for you to walk over a gap. When you are across the gap, walk towards the screen and you will find a ledge jutting out towards the screen. At the end of this ledge you will find the design.
Design : Mithril Disco Phial
Level/Location : Minas Tirith
Cost To Craft : 16 Bricks
How to get : At the top of the White City there are seven targets scattered around. Hit each one with an arrow and the design will appear at the top of the citadel. You can then use a high jumper to get up to the grab rails and jump up to reach the design.
Design : Mithril Bottomless Bucket
Level/Location : Edoras
Cost To Craft : 16 Bricks
How to get : Blow up the Mithril rocks that are blocking up the door to one of the houses near the Golden Hall. You can then walk into the house to get the design.
Design : Mithril Camouflage Tome
Level/Location : Amon Hen
Cost To Craft : 16 Bricks
How to get : To the east of the save point there is a large amount of water. On the other side of that water there are some beams that you can use to reach a small island with a campfire on it. Next to the campfire there is an orc holding the design. Beat him up and claim it for yourself.
Design : Mithril Spring Boots
Level/Location : Rivendell
Cost To Craft : 16 Bricks
How to get : There is a place where Gandalf can stack bricks so you can reach a higher area. When you are up here, look over the edge as you walk along it and you will see some grab rails leading down into a hidden alcove. Drop down into there to find the design.
Design : Mithril Skeleton Sword
Level/Location : Weathertop
Cost To Craft : 16 Bricks
How to get : Break through the opening to a cave in the side of Weathertop, to find the design inside.
Design : Mithril Hairbrush
Level/Location : Bree
Cost To Craft : 16 Bricks
How to get : Break open the door that is locked by the Morgul padlock and you will find the design behind the door.
Design : Mithril Paintbrush
Level/Location : Hobbiton
Cost To Craft : 16 Bricks
How to get : Find the fishing pier in Hobbiton and use Merry (or a character with the Mithril Fishing Rod) to fish this out of the pond.
Design : Mithril Ice Sword
Level/Location : Isengard
Cost To Craft : 16 Bricks
How to get : In Isengard there are some rocky hills to the north of its walls. Have a high jumper head up them, above the guy with the fetch quest. You will find a tomb half way up that you can break open to get the deisgn.
Design : Mithril Fireworks
Level/Location : Mordor
Cost To Craft : 16 Bricks
How to get : Go to Barad-dur and look at the arch above the bridge leading into the fortress. You will see three grab rails. Have a high jumper use them to scale the arch and jump onto the beam at the top that leads towards the tower. Walk along the beam, to the end to collect the design.
Design : Mithril Skeleton Bow
Level/Location : Lothlorien
Cost To Craft : 16 Bricks
How to get : In Lothlorien there is an elf with a fetch quest, but he is hidden behind a gate. You will need to have a strong character to pull the orange handle, to get into him. When you have gained entrance into this small room, hit the crate behind the elf and the design is inside.