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

It just goes to show you that things had to be analyzed carefully.

We don’t know how the UK worked their pressing plants. Did EMI/Harvest handle their own pressing plants the same way they handled Canadian or US pressing plants? Or where the pressing plants owned and run by private concerns, outside of the property holders?

This information is, generally, very difficult to find.

Your experience, seems to indicate that some UK labels did the same as they did when dealing with the huge US market. It might be that proximity to the EU, for UK property holders, may have caused them to adopt a single/common strategy, overall, that caused the Canadian pressings to be among the better out there.

Or that all I'm speculating in this post is completely misplaced and the reality was something else altogether. Ie that the hardware was not as good, or badly run, or that vinyl pellets were hard to come by or that the UK plants tended to use more recycled material in their pressings, and so on. Lots of details to try and find.

@teo_audio - you aren't off the wall on this. Discogs has pretty detailed info about EMI pressing plants and also covers the Philips/Phonodisc plants. 

I know from the history of Island Records (which did own a pressing plant at one point that was previously owned by EMI) that Island did use Phonodisc/Polygram and switched to EMI at around the same time that the pink label changed to the pink rim. (You can tell by the deadwax but it's not definitive since in the UK some older metal work was still in use- thus, UK pink rims with Phonodisc/Polygram nomenclature). I know Island UK also used Orlake for some of the pink labels- yet again different nomenclature- an independent plant as far as I know. As to ex-UK, a whole other issue. 

There was also a thing about getting early UK Harvests without the EMI logo- I have a few of those. 

The relevance of this was that when the "youth explosion" really took off- no more Perry Como, but post-Monterey Festival-- Island, a small independent label was eating the major labels' lunch. Chris Blackwell had an ear and was tuned in. The big labels needed to create imprints for this more "progressive" (as used in the past, not all "prog rock" as we know it today). Thus, Deram (Decca), Harvest (EMI Group), Vertigo Swirl (Philips),among others. 

For me, this is constant, ever continuing learning experience. 

And in re Canada, there's not a lot of info-- I found a scholarly policy paper behind a paywall that said Capitol EMI established their first plant in Canada in 1976. Another source on Capitol said that they used an RCA plant for pressing in Smith Falls, Compo may have pressed some- it was the largest independent in Canada, it was purchased by Decca, and Sparton, which did Capitol records before EMI bought them. The convoluted corporate history indicates that eventually the Capitol name was dropped for EMI's Canadian operations. 

I saw very little to direct me to Canadian pressings of Harvest imprints. If you look at an example--Roy Harper's Stormcock- a cool record, it was not released in Canada until 1978 (UK is 1971) and says manufactured by Capitol Records of Canada. I suspect one could track down this information on an album by album basis on Discogs. 

That's all I got. Phew! :)

@whart 

keep these stories coming!

I have many New Zealand pressings of various qualities. The best are early stereo classical records from EMI made from UK stampers and have matrixes that correspond with the first pressings from Columbia or HMV. These sound amazing and the only time I've had a chance to A/B one with a UK original (SAX 2368), the NZ version sounded essentially the same but on quieter vinyl (so better). Obviously, I can't claim this will always be the case, but the thinking is that these were made in such small quantities and by subscription (so no wasted copies) they used the best vinyl and paid the closest attention possible to the pressing process. Who knows? New Zealand Deutsche Grammophon are often made from German stampers and usually sound terrible, so it's not all good news.