how were copies of vinyl made in "third-party" countries

With all due respect, it is not just masters, mothers, and stampers. The first step in making LP’s is for the mastering engineer to cut a lacquer from whatever the source is. From the 1950’s onward that source was most commonly a tape copy (hopefully a 1st-generation, but not always) made from the 2-track master mix tape, in the record industry called a "production" master tape . The lacquer (a "positive") is then plated (and now referred to as the "metal works"), and the process of making fathers (a negative), mothers (a positive), stampers (a negative), and finally LP’s (a positive, of course) begins. A google search will lead you to deeper details.

A production tape sent to a foreign country will be used to cut a lacquer by whatever company has the rights to manufacture LP’s for their region of the world. So the same LP title can be manufactured from dozens of different lacquers, and fathers, mothers, and stampers, and of course pressing plants. Look through all the listings of the different versions of LP’s for any given title on Discogs. With some titles the numbers are staggering.

+1 @bdp24 

@bdp24 

"A production tape sent to a foreign country"

OK, so if it was 1s generation, then it was "original", with 2nd generation, was there a loss?

Would they have to send it back to the owner of the tape? And the owner would trust x number of countries with it? (Back then, the record companies in Eastern Europe were state run.)

Also, could they have also sent the mothers, stampers?

Also, could they have also sent the mothers, stampers?

I could be wrong, but the master tapes are not going anywhere. The master disc is made from a lathe cut lacquer and they can make a few masters if needed. I think I said it wrong earlier. The record stamper company would get a master disc. I wasn't in the industry so if I'm wrong I'm willing to be corrected. 

in any case, how do they sound? Content/artists you enjoy, original recording originally done, If enjoyable? involving? well done!!!

There is always the potential for a company to license content and them ,improve' it, 'enhance' imaging, .... Again, if enjoyable, nothing 'odd', there you go. Or, what did they do?

Something wonderful, perhaps research and find original issue, see if importantly better. If so, then replace other favorites.

IOW, unless a professional perfectionist, search for just a bit better can be distracting, finding other wonderful content would be my approach.