Here is the full list of all 11 Timpus treasure achievements.
Go through all of Mari's personal items
Go through all of Sandy's personal items
Go through all of the Mayor's personal items
Go through all of Timpu's personal items
Go through all of Rudi's personal items
Inspect every book in town
Go through all of Luca's personal items
Go through all of Kiara's personal items
Go through all of Mort's personal items
Visit all the graves and tombs in town
Inspect all the newspaper articles in town