|Photo courtesy Camille|
According to one website I found, this Koh Lanta Community Museum (พิพิธภัณฑ์ชุมชนชาวเกาะลันตา) was opened in December 2007 and is open daily, yet for Camille it looked like it has been quietly closed down in the meantime. Hope it is only a temporary closure, or a misunderstanding by Camille - I'll keep a look on his blog if he can find out any more details.
The building looks rather similar with the historic province hall of Nonthaburi, which is located right at the Chao Phraya river next to the Nonthaburi pier. Though the building there also has parts where it isn't restored that well yet, it has the local museum for Nonthaburi inside which is very much worth a visit, even though it is still only covering few rooms and is planned to have many more rooms and exhibits.
The modern district office of Ko Lanta is in the middle of nowhere still on the mainland, from the satellite image in Google Earth it looks just like most of the district offices today.