Found this presentation

[theSKSguy45]

A general overview of sks production, I thought it was presented well https://youtu.be/i41Q2TKsUhE?si=1i9dw8RO-qzdO8q2

[running-man]

Mostly good introductory overview. 

I don't quite get the Poyer/Kehaya love.  The presenter (Stang3787) also thinks the new Layman book is the "ultimate SKS collectors" guide.  Maybe because that's the only two that are out there with respect to reference books.   

I take offense with his "Ethiopian warehouses exported tons of SKSs" (~31:30 in the video) when it's clear he's talking about the "Royal Tiger" or more likely CAI Sino-Banian imports from 2012-2020.   The "you can't import them unless they have been out of the country for 20 or more years" thing is pure rubbish too, but what are you going to do?

Mostly good though, his M21 is fairly nice.