1979 Yamaha XS750 triple. 20k miles. Shaft drive. Guy is asking 1900 but there’s a lot lf minor cosmetic imperfections and I don’t know enough about the service history ot give him more than 1500. Anything else I should look for? These things are  abit rare and quirky and this is the sort of bike I was looking for when I got the grom - quirky, weird, different, and a bit rare. Looking to buy before the end of the week.