Austin Behlert did some cut down S&W pistols, I handled one many years ago that was a 39 modified in a similar fashon to the Devel. His guns were only different in the way the slide was shortened, I think he would not just cut off the end of the slide and fit a bushing but actually remove about 3/4 in. from the middle and then weld it back together. One thing that always stood out on his guns were the built up finger grooves on the grip frontstrap.
