The body numbers on the car in question are correct for a 1968, and they DO match the fender tag for the car. Someone used a 69 bee to replace a lot of parts on the 68 bee. The original engine and auto trans were replaced along with the K frame, the 383, the 4 speed. The Ramcharger hood replaced the 68 bee hood. Most likely the rear seat was also used out of the 69 bee that all the other parts had been sourced from so that would explain the 69 buildsheet being in it.
Matt