Thanks for all the replies. I have the original Heuer-buckled leather strap, the bracelet was installed by the PO. I also have the box and all papers for the watch. There is even the original clear plastic protector that came on the bottom and the warranty card stamped from Herkner Jewelry. Unfortunately, it was never filled-in, so I have no reference for the serial number.

Take a look at the back:

I am not an expert, but the relief on the engraving looks reasonably deep and defined. The satin finish appears as though it is original.

The only thing I found inside the caseback was an "S" stamped inside.

I know that the second owner had the watch fully serviced last December. He is a trustworthy, knowledgable fellow: He never indicated that there was anything unusual about the watch. Perhaps the caseback was replaced..?

This thing is truly an enigma!
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