I have four M32's and a fifth set of barrels that did not come on any of the guns. They all swap at will on any action. Further, I've used a new K80 barrel and forearm on one of the guns and showed another shooter I could drop his new K80 barrels on another of my M32's and use them as long as I used the forearms that came with the K80. I'm constantly amazed that shotguns made in the 1930's are so interchangeable and that Krieghoff is still holding the same dimensions after all of these years.
That hasnt been my experience at all and several times I have had to have Krieghoff International fit barrels for these early guns and they will tell you that once fitted to one of the early guns it is very difficult to get the right fit to another or multiple guns