That "anvil" thing strikes me as a mistranslation. Somehow I can't imagine cutting up an actual anvil for source material, which ain't easy.
Surely there were other sources of suitable scrap. I used to pick up all kinds of raw materials for my shop around building sites, railroad tracks, repair shops, etc. I once built a horizontal steam engine out of an MG brake cylinder, just as an example.
Gotta admire his mech-tech mentality though, regardless.
I note that in the top-break revolver, the muzzle opening doesn't match the holes in the cylinder, which are much smaller. I doubt that it's a result of photographic distortion. So what gives there?
Terry