DT1s aren't real flash as serious pre-75 racers, but anything is better than sitting on the sidelines talking about competing!
They're quite good (not brilliant) as pre-70 race bikes, but you need a square swingarm and a non-reed barrel to be pre-70 legal. Both these bits are relatively hard to find.
The one on EBay looks to have forks from a monoshock DT250/400 which are too long and not legal for pre75 (still got about the same travel though, so you might get away with it).
Seat bases are hard to get - if anyone is making re-pro ones, I'd be very interested myself.
Everything else is easy enough to deal with.
If you're looking at a low budget pre-75 racer, I'd look at a DT250A - they
are basically an MX250 with a lot more (easily removed) crap hanging off it. Parts are easier to find than DT1 stuff and they're a generation newer (albeit still quite closely related).
Plus the motors are very similar to the later YZ250/IT250s, so their better ratio gearsets and ignitions should fit.
