Dug out my Collectible Auto with the Squareback story. It's Vol.1, No.3 from September 1984. Allegheny-Ludlum got together with Budd to do up those two stainless ones. They were the last two 1960s because the stainless wracked the dies up. This article states that one was sealed in a time capsule but I've read since somewhere that both are still owned by the company and occasionally used. A-L has done this in the past with a '36 Ford Sedan and a '67 Continental. That last makes me wonder as the '67 and '68 Continentals were basically the same. There wasn't a totally new Lincoln until the '70s came out.
Bill Banaszak, MFE