Yugoslav M67 Details

I have a few questions regarding Yugoslavian M67 Ammunition. First, what year was the switch from the old clear primer sealant to the new milky red sealant? Also, i have examples of M67 headstamps from 1968 to 1998 from JNA stocks, and some have IK vs the backwards NK for Igman, the headstamps with IK if memory serves me correctly all have a two digit year, some are concurrent with the NK four digit year. Were these two diffrent factories, two diffrent lines at the same factory, different contracts/destinations or? has anyone seen the crates or boxes for the IK headstamp and do they indicate IK in the lot markings on the box/crate? Also what are the confirmed years for PKI? i might have some data to add to that as well once i go through all my collection. What calibers is the “nr” factory known for? Any m67 ever? And lastly, is SMB known on m67 ammo? other than the m67 made under the Reserve Capacity 1 moniker? Thanks in advance for any info. I have some duplicates in M67 if anyone is intrested in any years or factories or needs any M1959 (Yugo M42) examples.

-Thanks in advance for any info.