Well, either wilfully naïve or unwilling to accept that he has been landed with a pup.

The movement is Heuer, yes.

The caseback is Heuer, yes.

The dial may be from an original Heuer Autavia 2446, yes.

None of those things are in dispute.

As for whether the movement fits the case, he is presumably aware that the Vj 72 isn't a Heuer movement and was widely supplied elsewhere so the fact that it "fits the case" proves little. And to me, that 13 ligne movement in that size case looks a little lost, even with the spacer in there. I'd say the case originally fitted a 14 ligne movement, potentially larger.

The Scatchard and YorkTime watches show original cases, completely unrelated to the case in question. The "One with the 3 crown configuration can also be seen here: http://www.yorktime.com/search?cid=17:sku=253" comment is nonsense - that watch is an 1163, with left-hand crown and 2 pushers, not 2 additional crowns. If the eBay case is original, perhaps the seller could explain what purpose the left-hand crown is serving on a Valjoux 72 where the winding mechanism is driven by the crown in its usual position on the right?

I would also invite them to give the serial number and model reference (with the dial looking to be from a 2446, it could be prior to Heuer adding model ref to the case, of course) from the usual places on the case. As these positions are widely known, I won't insult the seller or his expert by stating where they can be found. We have a sizeable list of serials we can check against to make sure it fits in the correct sort of area for model and date, which will be somewhere between the Autavia's introduction in 1962 and around 1971 when the Vj 72 was finally phased out in favour of the 77xx family.

Lastly, given that date range, I would invite them to find the model in Heuer sales literature of the time - between OTD and various other sites, we have pretty much year by year coverage of the period. It's true that the occasional dial variant doesn't make it into print, but a discrete model of a watch as significant to Heuer as the Autavia would definitely be included.