I once removed sling swivels from a Spanish sidelock. Keith Kearcher welded in the two holes in the bottom rib and rust blued the area so it was almost invisible. I was able to fit a matching piece of walnut into the hole in the stock by sanding it to fit, epoxying it in (sawdust in the epoxy), and sanding it flush. Once it was finished over you really had to be looking to notice. The gun has moved along to another so unfortunately can not post pictures for you.
I've had Keith do two for me. I couldn't tell on the barrel's on either gun. Fantastic job. I think he charged to $100. PS. I had a stock guy install an oval. It's wasn't great and wasn't awful.
