I very much enjoyed your Hi-Fi memories DJ360.
My Beatles LPs were all bought on the day of release so I assume they’re first pressings. I usually bought them from Boots on Pelham St where as a Boots employee (D10 Beeston 1968-72) I could use my discount card and get 10% off. After Sgt. Pepper I bought Yellow Submarine, The White Album, Abbey Road and The Let it Be boxed set. I'm quite OCDC so they are in outstanding condition although not mint because I've played them all (carefully) a good few times. As I'm sure you know the later Beatles albums in mono are more valuable than their stereo counterparts because they were less common in the late 60s.
My first wife's father was very into H-Fi and In the late 60s he had a Linear Stereo 30 (transistorised) with some excellent speakers and high quality turntable although I regret I don't remember the manufacturers. It was the most impressive sounding setup I'd heard up until then. He also used to play his Uher Report reel to reel through this system. Later on he bought two huge floor standing Wharfedale Teasdale speakers and a Quad amp which was stunning. He then added two more Wharfedales and a Pioneer quadraphonic amp but as you may remember quadraphonic sound didn't really catch on.
I well remember the early Beatles stereo albums which were a Godsend for a guitarist/vocalist such as myself where you could hear the instrumental parts and vocal harmonies so much better.
IIRC when the Beatles albums first came out on CD in 1986 the first four were in mono but the fifth, Rubber Soul was in stereo and the vocal/instruments separation was preserved. When the albums were remixed/remastered in the early 90s the sound engineers put the vocals in the centre of the mix and also adjusted the stereo image of the instruments.
Finally in my collection of Beatles LPs I'm very fortunate to have a first pressing copy of Beatles for Sale which was given to me by first wife's father. The cover shows slight signs of wear but the record itself is in excellent condition. The vocal/instrument separation makes for very interesting listening.
I bet the other early albums are also fascinating to listen to in stereo.