The Kalt KG 22 is what is now the Zenoah G23. I will see if i can find an article of when the G23 was first reviewed and where they referred to it as basically the Kalt. As i remember, the only difference was that the prop shaft length was different. Since the prop shaft is actually threaded into the crankshaft, like the K&Bs, changing its length is no big thing, only the thrreaded prop shaft rod and the prop hub need to be different. You indeed have made a good deal at $50 for both plane and engine, as long as both are servicable.