I have mounted quite a few Tufo tubulars and I still sometime double check to see if the tire isn't really a 650. These tires do seem impossibly small when new. If you have time, I've had luck pre-stretching them for a long (months) time. Once taken off the rim, they've gone on fairly easily if mounted within 24 hrs. After I apply the rim coat and the glue is dry, the tire goes back on a clean rim. When I to waited longer than a day, they seemed to "shrink" back smaller.
Mounting Tufo tires previously used on wheels that have been ridden has been very easy.
Tony Welch
Indianapolis, IN
USA