Jason Spencer at Gunco in Nepean has done this. I've seen the results, and they were superb. He used 2 1909 Argentines, and wound up with one magnum length, and the other .22-.250 size. Outside the stockline, you could not tell that the actions had been altered. One action was for his own use, I think he sold the other. No idea about cost, but this is a serious project.