If the claim is that it's the exact same watch/dial from the publicity photos, then I'm not sure. It's sure entirely possible that more than one prototype of each was made and also possible that there could have been minor variations between them. Either way, it's certainly a rare watch and I think there can be no questioning it's authenticity from that period.
I think it's a wonderful discovery, and something that over the years has been dismissed as being the fantasy of the art-work department. But the "first ever" claim is over-hyped, as many people have pointed out, which is a shame because it's a great find irrespective of whether it is that watch in the photo or not. For production watches, Jack Heuer once told me that minimum batch sizes was around 100 . Was this a production watch or a prototype dial? If it was a one-off, then the claim must be right, but I would have thought the more likely answer was that a "handful" of dials/ watches were made, and as soon as you believe that more than one was made, it's then impossible to say which watch is shown in the photo. You then have to believe that after the photo was taken, the watch was then disassembled- if it was a prototype, it was probably simply thrown out! The guessing over which watch is photographed isn't the main story here- it's that a collector made a really interesting discovery which has changed some of the history of one of the most important Heuer models. EDIT On re-reading Jeff's article I'm not 100% clear whether when he says "Jean-Luc's watch" he means this exact watch, or whether he means "this version of the Autavia". I'm assuming he means the former.
Very good take on this David. I concur, the whole find is what make the story interesting and special.