Bill, any chance you can make out anything on the ship to on the yellow label? Is there any postal or shipping date on the box? I’ve researched this since mid 70s as I’ve had a set since then. There was never a GM part number. They are not mentioned in Assembly manual. Original owners, some who still have the cars today, did not get them. Dealers who sold new cars never saw them or a memo how to get them. They were designed by Campbell Ewald the ad agency for Chevrolet. They were shipped to the track, the central office or dealers who were prepping the cars in Indy to be installed. What makes yours VERY interesting is the CO Dicks Company of Michigan failed to exist under that name as of July 23, 1971. I believe there were reproductions in the 70’s as I believe mine are reproductions but I’ve had them from the mid 70’s Let me know if you can read anything off the yellow label. Bob