Hi Jeff, really needs to be seen in the flesh to be honest, it's certainly subject to opinion! But it's things like the unmarked seat tube at the point where the derailleur mounts, condition of the underside of the downtube and unmarked face on the front forks where the caliper goes which has formed mine, I'd expect some tell tale marks in these areas even from minimal use or even if parts were fitted for only a short period of time.
Drop me a message when your next down and if it's still here your more than welcome to have a look, I'm in Manningtree to be specific.