regulator repair options

[suddha]

My wife's Mares Abyss first stage needs repair. The surface of the large nut that holds the yoke onto the reg body is gouged and doesn't seal against a tank valve. This must have happened when the dive boat hands were swapping tanks in Cozumel at some point (another reason to set up your own gear).

In any case, a local Mares dealer is trying to source the replacement part (the nut is a swappable piece) but having no luck. We hate to have to buy a whole new first stage. I am wondering if the nut could be removed and the surface machined or carefully filed down to remove the gouges. Any thoughts or other options? Anybody know a good machinist?

Sorry I don't have any photos since the reg is at the dive shop now. I hope you can imagine what I am describing.