I was wondering if anyone knows of a resource out there to help identify vintage hoops, particular 60s era triple flanged Ludwig. I've got a 66 Ludwig kit here with some possible unoriginal hoops, and it'd be nice to know exactly what to look for when trying to verify originality. Like detailed images of holes and flange style, thickness etc. Ideally I'd like to be able to look at a hoop and quickly tell if it is or isn't Ludwig, in the same way I can look at a bass drum tension rod and immediately tell if its Ludwig or an Asian knock off.