I bought an '81 gs450 for a decent price. It has been painted, seat slightly modded, has lowered bars (3in down and don't like em) but is mostly stock. I can't seem to figure out what model letter it is? VIN hasn't narrowed it down and there's no badging. Is there any tell-tale thing to look at to help me out or should I post a few photos for you experts to help me out? Sorry if the answer is super obvious, I'm newish to bikes in general.