68 firebird project car, still has original carpet, pannels, etc but oddly the drivers seat has the back rest release lever on the wrong side. It looks exactly like the passenger seat. What seems strange is that the seats look like a matched set. Parchment seats, both are worn exactly alike including the plastic back support pannels. This was an early 68 convertible build so is it possible they ran out of parchment driver's seats on assembly line and stuck in a passenger seat as a replacement? just seems odd that the interior is basically all original and doesn't appear to ever be removed or messed with. I would assume if the seat was replaced later in life with a parchment colored passenger seat it would be noticeable that one would be in better condition, etc. anyone believe my theory of assembly line substitution?

I highly doubt that would have happened. The driver's seats tend to wear out first, so likely a PO swapped one out with a 'nice' passenger side.

I would think the seat 'slide' release would grind against the hump. How is that situation looking?

the slide handle is in the correct "drivers side" location. It's only the seat back release lever that is on the wrong side. Perhaps if PO replaced driver seat with passenger seat PO retained the driver seat track and used it on the replacement "passenger seat"? I assume seat tracks are interchangeable between passenger/driver but I have no facts that would be true.

It would be more likely that is what happened.

I don't think the slides/adjuster are swappable from one side to the other...the seats however may be able to be swapped. seperate components. don't know for sure though???