That's too cool!!! I have never done any kind of motocross, but it always looked like it would be a blast!!! Vintage would just make it that much cooler!
Being in Alaska, I have done vintage snow machine races though. I've raced twice now in the Fairbanks Tired Iron on a 1979 Kawasaki Invader 440. Finished 8th last year. Was a lot of fun, and really, it's just cool to be out there racing on such old but still wicked fast sled.
Seeing all the other "old stuff" is cool too. Last I heard they were talking about maybe doing a vintage motorcycle ice-race for this next year, in addition to the normal sled events. If they do, my little 100 might be getting studs...