INAD issue - Wrong item sent from the UK to US - How to deal with return?

So, question, here. Bought a watch from a UK seller. I've done hundreds of watch imports over the years so I am seasoned at dealing with import. This, however, is the first time I've ever had a seller send me the wrong item (and, in particular, a watch).

I am curious how eBay handles returns on these things when it comes to the return and the import fees paid. I'm guessing that an INAD will not force the seller to reimburse import fees, correct?

I am just debating on doing a straight return with the seller or going the INAD route. I'm guessing I probably an SOL with the import fees since I would imagine there is no way for eBay to force them to cover that. Seller does offer returns, but I feel like seller is kind of overlooking the fact that any return is still going to be a significant hit to my bottom line.

So is INAD the best route in this case to try and pressure the seller to work with me? I have been buying/selling for years on eBay (15 years) and this is actually the very first time in a few thousand transactions that I've ever had a significant issue.

I was hoping to get this amicably done with the seller, but the seller doesn't appear to want to actually work with me even though they clearly sent the wrong item and even admitted it in writing.

Just sucks that I guess I'll be out a fairly significant sum, here, regardless of what route I choose. The best route may be to simply re-sell the watch in the US, but that could mean waiting a decent while.

So, yeah. INAD? Straight return? What is the best route, here?