Neil, in your shoes what I would do is edit the auction description to state that you've been made aware that it is a redial. That's both fair on the bidders and gives you a little bit of cover - at least they'll know what they're bidding on if it's explicit in the text, and less likelihood of comebacks once it's sold.

You may get some of the bids cancelled but at least some of them probably know exactly what they're bidding on already, and either have or can lay their hands on a replacement dial. They're not the hardest Heuer dials to come by. And as you've been candid with us and come forward with the serial number, if it does get sold on again, we can see if the next seller reciprocates by disclosing the replacement dial!

So that's what I'd do - add to the description so it's perfectly clear it's a redial, then let it run its course. Your watch, so up to you what to do next - you might decide you could bond with it with a new dial, or replace the dial yourself and relist. Depends on if the bids cover what you paid too, of course - sourcing and fitting a new dial will run somewhere around £200-£300. You might see more than that back relisted with a replacement original dial, you might break even or perhaps lose a little. I think I'd opt to leave the decision about the dial to the buyer - they may prefer a black one!

Good luck with whatever you decide - it's nice that a seller's not coming here and insisting everything is original and correct.