I neglected to cover one other factor in the LP sound equation, that of the mastering engineer. The vast majority of LP titles were mastered only once, and all LP’s of that title were made from that one original lacquer (what a mastering engineer "cuts". After that the lacquer is used as the source for for the following steps in LP production).
However, some titles were mastered more than once, with the resulting lacquers then producing completely different versions of the title. The most famous example of this is Led Zeppelin II. The original lacquer was cut by Robert Ludwig, and can be idenntified by his "RL" initials cut into the dead wax of LP’s made from that laqcquer. Ludwig cut the lacquer so "hot" that the record players of many 1969 listeners would skip. Receiving a lot of returned "defective" LP’s, Atlantic Records had another engineer cut a new lacquer, one less hot. The RL pressings are now quite collectable, worth far more than non-RL pressings.
One album I love is Truth Decay by T Bone Burnett. The album was released in 1980 on Takoma Records, which was at that time being distributed by Chrysalis Records. The LP contains not only great music, but in great sound. While browsing in the bins at Moby Disc in Sherman Oaks in the early-90’s, I saw a copy of the LP for cheap, so bought it in order to have a back-up copy. I didn’t notice that though still on Takoma, THIS copy was being distributed by Allegiance Records. I played the LP, and as the last song on side 1 ("Driving Wheel") came to it’s "false" ending, I waited for the musicians to come back in one by one, leading the song to it’s eventual fade-out. What I instead heard was.....nothing!
Allegiance had had the LP remastered, and whomever the mastering engineer was didn’t realize the false ending was just that---false. When cutting the new lacquer he heard the music stop, so he cut off the side at that point. When looking for a copy of Truth Decay, make sure the cover reads distributed by Chrysalis Records. ;-)