Back in 1994 I bought this Mauser Destroyer Carbine that had been someone else's project, at a gun show for $200. (At the time, unaltered surplus Destroyers were going for about $100 due to being chambered for the uncommon-in-the-USA 9mm Largo.)
This gun had been converted to .45ACP with a new barrel (still in the white) and an altered 1911 magazine made to fit the magazine well. The bolt handle had been cut off, bent, and clumsily rewelded. New sights were put on with a peep of unknown origin on the rear of the receiver. The forward hardware for the full length stock was stripped and gone, and the end cut more or less flush with the barrel. The top picture is how it looked when I bought it.
I took the gun to the range a few times and it shot pretty well, in spite of me finally noticing that the front sight was loose. I have little to no gunsmithing skills so I put it away, unfinished, for a later day.
In 2021 I finally took it to my local gunsmith that I had found who does reliable work. I had him clean up the metal, work on the action a little, bead blast it and blue it. He doesn't do stock work so I expect one day I'll finally cut the forend back to an appropriate length, shape it, strip, and refinish it.
This last picture is one that I found on the internet of someone else's gun, with original barrel and sights. It shows more or less what I'd probably try to make the stock look like.