I doubt its been tampered with, I thing it just rolled over, once it gets to 99999 it rolls over to zero and starts again, and truthfully, If that car runs good looks good and stops good, buy it, its a steal now at 6 grand ok? the drivers seat does not lie, no matter what, somone was always in the drivers seat, so look at the switches and stuff, look at the turn signal, the little pain symbols on the heater controls, what ever someone would have touched, at 138,000 I would expect the seats to be kind of worn looking, and if someone changed the brake pedal its either brand spanking new or with 100 thousand plus miles, it would have some obvious wear, that is a great year for corvette ok? the engine, tranny and rear end were tough as hell and 138 k is nothing, the thing probably hauls butt. I think for 6 k you could fix the seats, get the car detailed professionally, fix any litte problems and put the thing in the paper for 15 grand, so you are not going to lose on this deal.