I found a report on a derailleur museum near Paris on a site of a vintage bike shop in Kyoto. http://www1.odn.ne.jp/~aaa65240/mpdd.html It says we can actually try all the derailleurs. Also found a report on Alex Singer at Salon de Paris 2001. http://www1.odn.ne.jp/~aaa65240/sdp2001.html
Takao Noda Hachioji Tokyo Japan