First type of the croatian copy of M-75 grenade was made using croatian made bodies for that grenade and using yugoslavian made fuzes for practice M-75 grenade(fuzes for VBR M-75).
At the beginning of production, engineers faced the problem that fuze for M-75 was much more complicated part for copying than body of M-75.

All info and photos © Goran.

The body of the M-75 was easily copied but the factories weren't able to make the croatian made copy of M-75 fuze in that short term, so they simplyfied production by using practice fuzes for yugoslavian VBR M-75 grenade.
The fuze mechanism was the same on practice as on live fuze, the only difference was the detonator.

Croatian army had large quantities of the practice fuzes, confiscated from ex-Yugoslavian people's army military bases located in Croatia.
The practice detonators from that yugoslavian practice fuzes for VBR M-75 were removed and replaced with croatian copied detonators.
So this grenade at the first sight looked the same as yugoslavian practice VBR M-75 (black body and the yellow fuze).The only difference from external appearance between this first type of croatian copy M-75 and yugoslavian made practice VBR M-75 was in the markings and the bottom of the grenade (it didn't have the hole at the bottom like
VBR M-75).
Inside, this grenade had the filling of PEP-500 explosive.

After a few months,croatian factories developed domestic production of the fuze for that grenade.
The production of the fuze was no problem anymore because the production of the fuze was divided between a couple of croatian factories (each of them was specialized in production various parts for the fuze which were than transported in one factory and assembled together).
Using that division of production parts for the fuze, croatian industry became capable to produce high quality copy of M-75 fuze with high work productivity. These new croatian made fuzes were made of black plastic.

The second type of croatian COPY M75 grenade was produced in much larger number than the first type of that grenade(with the yellow fuze). See the "