Kreighoff in PA has the ability to silver solder inserts on the rotating half rounds on the K gun barrels, they then remachine them to factory specs. Could they fit a K barrel to an old 32, sure. Would they do it? I doubt it and the cost was $400 a few years ago. I would go to Simmons who has made barrels for both guns. I believe that they have the same skill sets and are open to more general jobs at a more realistic cost. I have been looking for a set of K-80-32 thirty inch screw choke barrels and can't find any under $2000, so get ready to spend some big bucks.
bill