I was sad to see on my virtual travels tonight that the Mahjong Museum (麻雀博物館) in Chiba prefecture was officially declared closed in 2017.
The main page of the museum website simply thanks visitors for their patronage and says that sales of mail-order merch have already ceased.
http://museum.takeshobo.co.jp/
There are no internal links off there but you can still access pages directly for glimpses of their historic collection.
http://museum.takeshobo.co.jp/houmotsu/up/index.html
The map here links to pages of history for Japan, China, Asia, Europe and America.
http://museum.takeshobo.co.jp/houmotsu/
Mahjong Museum closed
Moderator: Shirluban