Zastava M93 12/70 was made 1993-2010.
SFRJ had Mosberg 500 (federal police, Croatian police, acquired early '80s), Ithaca 37 (army, mid-late '70s), Remington 870 (Belgrade police, late '70s). Browning Auto-5 (federal police), SPAS-12 (federal police, early '80s, very small number), SPAS-15 (army, late '80s). Possibly some more, but information about police armament is hard to find, as they acquired a lot of weapons in trial batches.
Edit - there were some Stevens 620 pump action shotguns in airforce, for bird control around airfields. Those were in IIRC 20g. IDK when they were acquired but it is possible they came in '50.