I did it to a Varsity, so I think it's a great idea. I can't find a picture of it on the InterWeb, but you can get a horizontal dropout mounting universal derailleur hanger at your LBS for like $5.00. It has a screw and a half-moon shaped deal that sandwiches it to the dropout while leaving enough room to adjust your axle fore and aft a bit. LooseScrews also carries them although as I recall, they are so cheap you need to order something else to exceed their minimum order! I mounted a older Dura-Ace RD to my Varsity and a XT to a Falcon. Works great.