Need some help for Luger's elder brother C96

[berkmberk1]

Granted its not a Luger, but they share certain commonalities - a certain rarity, and difficulties finding talented professionals to get certain things done. If anyone will know, its someone here.

I recently picked up a C96 Wartime Commercial model. I do believe its restoreable to an extent. The frame, lock mechanism, and bolt match. The barrel extension doesn't. I'm going to reline it to shoot it, but here is the rub. I'd like to refinish it (its pretty much gone) but the underside of the barrel is damaged. The seller said it was pitting. However, what ever it WAS looks like someone took an rotary grinder to it. (see pic). I read some older posts here about filling pitting (not the Grand Canyon) with different forms of metal work/welding and I was wondering if anyone can refer me to someone who does this sort of thing on firearms. If that isn't viable, I guess a reference to a GOOD Smith that does draw filing might take a noticeable amount out before refinishing