I have many LP’s from the countries you brought up as examples….Yugoslavia, Holland, Hungary, Russia.
Holland? Philips manufactured in Holland. Some of the best recordings and pressings you will find consistently.
Hungary? Again, some of my best recordings and pressings by Hungaroton
Russia? Мелодия. Again, one of the best recordings and pressings you will find.
I will throw Czechoslovakian manufactured LP’s in there as well, Again, very well recorded and pressed.
These countries really care/cared about the quality of their reproduced music. In general, much better than what was manufactured in the USA overall.
In terms of ‘third party’ pressings, I have no idea. But in general, these countries have produced some of the best.