That is FUN NEEE right there? I guess? I mean I doubt it. the bikes that are the cheapest and easiest to get parts for, will be the bikes that end up with a "solid" big class. IMHO in the USA, "Air Cooled Mono" I would think, that would have been a good 86-87 era TY350 class. Maybe with Montessa and Fantic occasionally? With the Yamaha, it seems most don't have trouble finding these complete and running. I guess it seems to me, that often used parts, like levers and other things that break wear out are still easier to find? I have had 2 of these, never had to search for anything for one, unlike the 2 Fantics I have (240 pro). We still see at least one TY 350 being ridden in Modern trials in our club, there might been 2 of them at a couple regionals. Never see a old "other brands" though, not in 10 years or more, though. but then again I only go to 5 states to ride, every year (tx, ok, ks, ne, mo) oh and visited, nm. But, I don't see this happening as such for the disc braked, air-cooled, mono shock class (aka after Yamaha quit shipping to usa?) The bikes other than Yamaha for the mono class (air cooled) seem to have vanished along with spare parts long before anyone thought of "vintage" classes for these bike, as in back when they were "modern" wouldn't you admit? Plus, I see people on say a 1977 Ty250, that they have almost as much money in, as I do buying a new modern bike every year. Don't act like custom (yet at home) reworking everything (for example work like even MotoBene did on his own modern bikes) is NOT expensive for most anyone else to accomplish... if they have to source it out, like many people would. OH, does the drum braked air cooled mono shock class compete directly with disc brake bikes? I assume so, but that leaves ya with disadvantages being on the TY, if it rains? What I see next could be some neat hybrids maybe? take a 77 TY and put that engine into a clapped out 93 gasgas frame, would that be legal?