Hold the presses!
We REALLY SHOULD STOP USING THE GENERIC "AK47" TERM FOR ANY KALASHNIKOV! It is highly confusing.
The AK47 ceased production in 1959. No furniture from the AK47 will fit any succeeding Kalashnikov designs, such as the AKM, the AK74 or the AK-100 series.
Since the AKM arrived in 1959, the commies have not changed the furniture patterns, so all furniture will interchange among standard Kalashnikovs. The Yugos did not adopt the standard in their AKM, and there are some specific exceptions such as the AMD-65 where the furniture won't interchange.