634xxx would be late April/early May build. Not all COPO cars were built with consecutive VINs. This was a small block car with a V8 that might have been built the same day as a COPO was, but the 10C in no way comes close to the VIN.
IMO, the trim tag did not come with this car.
However, a photo of the VIN would be helpful.
No way this was ever a COPO, and not represented as anything but a nice driver, which it looks like to me.
