Left: CZJ made one has each individual holes,
Right: Pentacon one has just square cut for them except the second version of Prakticar 50/1.8.
Probably there were many left over parts when PENTACON started to make the second versions.

The iris blades of CZJ made lenses are shiny, but PENTACON made ones are matte black.
In order to be CZJ made lens, it should have all these features together at the same time.