Dan,
Off hand I can't remember for sure. Might have been the Kansas City built red convertible. However, I've bought many sets over the years and some had them, some did not. I probably had six extra sets plus the ones that were in the cars. I may have just had a collection and saved them up and put them on later. Regardless, if one Buick had them, surely there must be other models, other years that would also have used them. Wonder if Chevy, Pontiac or Olds would have also used them? Salvage yard search?
John