I don't wanna say it, but there is no other way to express my joy... We was right.
Cross nation compatibility I can see.. how else would they do it with "licensed" copies. Would be interesting to try to verify. If one looks, it wasn't until Russia and China didn't get along, did the SKS change to short lugs, press fit barrels, spike bayonets, their obligation to make it Russias way was gone. Like Yugoslavia, they did it their way, just faster, cheaper, and with less material.
I believe with Yugoslavia's past experience in arms building, Russia handed them a rifle and a spec sheet and said make this. They probably didn't need machines, setups and education to do it like the other nations. They had tons of machenry from WWII, How many years, like 30-40 plus, did they make Mausers and other weapons. They knew how to work with extractor cuts and head space stuff from building massive amounts of Mauser rifles. As long as they stuck to the Warsaw pact caliber 7.62x39, that was what was important, like Czechlosvokia and the Vz52/57 and the Vz58. The Yugoslavian Ak is another example of going against Russia's master Ak design.