SGT...great point on the carding and welding to fix up the barrel engraving. A while ago I had an ideal grade 16 that I was able to buy for a song because the safety wasn't working and there was some unusual pitting on the exterior of the barrels near the breech. I knew my gunsmith could fix it up pretty cheap so I bought it and brought it straight to him. He welded some extra metal where the pitting was, smoothed the area and touched it up with blue. Then he fixed the safety. He charged me $75 for his work and when I got the gun back you couldn't tell it had ever been less than perfect!
I wouldn't use $75 as the basis for estimating this repair. I send my gunsmith a lot of work and sometimes he charges me quite a bit less than he's worth.