So I'm buying this bike, which is a 1975 CB750F. The fork lowers and engine are black. I haven't seen it in person, but is it safe to assume this isn't the stock engine/fork color? I know later F's went black, but I don't know when. Maybe a later engine, but given the stator cover is black also, I'm betting on a paint job. Oil filter cover is black as well. Maybe it was done to blend in with the fairing?