Found another Skipper with unusual case at Heuer Factory Archive!
During the Heuer Collector Summit in La Chaux-de-Fonds we were given the opportunity to have a closer look at some vintage heuer watches from the Tag Heuer archive and I was amazed to find a never seen manual-winding Skipper 73464. This Skipper was not cased with the usually 7736 case (the case reference 73463), seems to be a 1564 case. Note the difference at the pushers and cut out. In addition to that the countdown register marking are different. I can only assume that it is a prototype or a very early production piece.