James,
I doubt very much that it is a 'parts-bin' special, it is such an obscure model, that even it does vex seasoned collectors, so for that reason, a parts-bin is highly unlikely.
What you need to understand is that at the time these were hitting the catalogues/the market, it was alomost as if Heuer were designing it on the fly and getting them rushed out to the catalogues. You can see various design changes over this period, too many to list, but as an example - bezel pip, no pip, cath hands, merc hands, 'swiss made' on the dial, nothing on the dial, English/French spelling etc etc etc.

I think your watch is all OK, except the crown - which is clearly wrong - Heuer didn't use signed crowns on their divers until quite late - around '84.. Speak to James Hyman - he should be able to sort you out with a correct unsigned crown - you'll need to check the movement type though.

PS. I spotted your watch on ebay - I was tempted myself!

Stewart
- Heuerville