I’m sure you know this, but just in case... Xpan won’t wind a film if you have your ISO dial set to DX and the film doesn’t have DX code or it’s unreadable.
Anyway, you could ask Hasselblad UK. I had my on/off dial replaced and bulb time extended there. They said that they didn’t know if the part is still available but agreed to forward the camera to parent company and it came back fixed.
Another option in Europe for me at the time was Wilco Jansen (he had the on/off switch part but couldn’t extend the bulb time)...