Queen vinyl matrix number questions

Hi everyone!

First off, let me clarify that I know squat about dead wax / matrix numbers. I just know they exist and they mean something. That's it...

I'm a Queen fan and I happen to have a few different editions of some of their albums on vinyl. I was sound-testing (just for fun really) different issues I have of the second album Queen II, a UK pressing (late one, from the 80s I think. The one with the "cream" color labels instead of the early big EMI red letters), a US pressing from Elektra, the 2015 remastered coloured edition and an cheap old version from Argentina (where I'm from).

When listening to the 4 different pressings I was actually pretty surprised to hear that the Argentina pressing sounded almost exactly like the UK pressing. Then I checked the dead wax numbers and they are almost identical to the UK pressing (YAX-4735 1 / YAX-4736 on the Arg. pressing Vs. YAX-4735 10 / YAX-4736 5 on the UK).

What does this mean exactly? did stampers use to be exported for this kind of things? As far as I know this record was pressed in Argentina and It's an official EMI local release. It does have all pertinent Argentina copyright information and such.

The vinyl on the Argentina edition feels even heavier and more solid than on my UK pressing. I know there has to be some sort of a catch, or maybe a more subtle sound quality difference escaping my ears, otherwise it doesn't make sense that these Argentina records are almost a quarter of the price from a UK pressing (at least here in Argentina that is) if they sound almost identical to UK pressings...

I hope somebody can illustrate me on this one!