Oops! I guess you have checked my site closer than I have... I know some of the shops do online sales but not sure if any of them will ship overseas and the web sites are often in Japanese. But your best bet might be Map Camera. They have the biggest inventory although they are often a bit overpriced. There is a dirty little shop in Shinjuku that would be most likely to carry these items but they are totally retro in everything they do, and don't have any sort of web site. When I'm back in Tokyo in the spring I'll try to remember to check it out sometime.