Whats on your turntable tonight?

Where do the "master" recordings fall into these different pressings. The ones from the late 70s

Here are a couple of good articles about reissues, remasters and repressings:

https://www.vinylchapters.com/original-pressing-vinyl-or-reissue/

https://waxtimes.com/repress-reissue-and-remaster-explained/

Elton John-"Goodbye Yellow Brick Road"

Speakers Corner-Germany

(I went to pull this out and realized I had like 10 different versions of this.  Direct-Disk Labs, MOFI, Simply Vinyl, Speakers Corner, US 1st, UK 1st, Japanese 1st, Belgium.  Also one of my DIT25).

Halfspeed masters! that's what they called them. Was that just a gimmick?

Half Speed explained:

https://thesoundofvinyl.us/blogs/vinyl-101/half-speed-mastering

Mobile Fidelity was the reissue label that more or less started that.  I'm a huge MOFI fan.