Not exactly Buick related, but I did find a front and rear set in the trunk of a 65 Skylark I recently picked up for parts, so maybe close enough. Kinda cool looking "Rampant Lion" crest and wondeing if anyone might know what these came out of?
Peugeot I'd have to think. How do I know this you ask? When I owned a rollback,Peugeot's were frequent fliers :TU:
I have a set of those in my 69 Riviera. They came in the car when I bought it in 1984. I think they were just an auto parts store item. Try finding nice rubber mats like that today. They're virtually obsolete.
Also found a like new '65 black dash pad in the trunk with the mats. Don't worry I won't be using the mats in my GS, though they really are heavy duty.