I ordered this FG(2) XR6 driver's seat-belt a few days ago...
https://www.ebay.com.au/itm/374291209483
It's comparable in price to what was the last item GT Legend was able to find for me (no longer available though, or at least now restricted). Mine was stolen from my front door after Aust-post delivered it, between the two hours it was delivered and when I went home early from work to collect it.
This one arrived today... That's very quick postage.
It's exactly the same as what came new in my car, came in a Ford box, same numbers on the label, same tag on the belt as on the original, except its date of manufacture is 2022, around February.
And it's effing fantastic, I now remember when I bought the car new - don't let go of the belt because it might hit the window and crack it!
And the now 10 year old one removed, I can see it's full of crud - no wonder it can't retract without being 'fed' back into the mechanism.