Cast your minds back kiddies, there was a time when whisky was Canadian or Scotch. Gas was leaded or premium. And ammo was British or American. None of those cartridges from the side we beat. Pfft!
I bought a very well converted double lug 1945 G43 (yup, the desireable model) that came with an extra long foreend hunting stock made by Fajen or Herters (forget which). The finish was buffed up smooth, reblued and the back sight ears ground off. A crime by today's milsurp collector's standards, but making an old worthless piece of wartime pickup junk into a reasonable hunting rifle by the standards of the day. Heck I saw worse jobs done to make FN49s into sort-of copies of FN C1A1s. Notice I said sort-of, because there is a lot of geometry and engineering that just gets in the way of a 100% version.
So, a 7.62x51 conversion? Not beyond conceivable.