I thought they had an offroad only VIN but I gues theyre old enough that vns weren't standard anyway and yeah usually you just need some kinda inspection to get em street legal.
IT's are fucking awesome bikes, really incredible, totally dominate the genre and era. Like the WR vs the XT, they were serious offroad enduro bikes, not just an offroadable streetbike. I've played wit h a few of friends and talked to several vintage MX folks who swear by them. IT400 is obnoxiously huge and still they upped it to the 425 and the 465 is worth a "what the fuck were they thinking", though some folks swear theyre the best vintage motos, and the 490? fucking piston's the size of a side dinnerplate. I gotta feel like that's way beyond too much for me.
The 175 and 200 I'd prefer, probably most common so you got alotta parts, very capable but personally I'd be on the look out for the 200, lots of good parts for those. they're so fucking gnarly