Looks like a beauty!
Any "1.TRZ" or similar "TR_" marks anywhere? They typically show up on the right side of the buttstock.
The Yugoslavian rifles have serial numbers, "assembly" numbers (the barrel number and matching), and "parts" (or lot) numbers on the various, uh, parts. I have a few of these Yugoslavian SKSs, but that doesn't qualify me as an expert, so others may add or gently
correct my descriptions