You never did say just what tracking force you had on the tone arm. That makes a significant difference.
Everything on the player was setup and adjusted by a local shop owner, I trust his knowledge more than my own on record players. And I feel the tracking is fine, I'm not sure what the counter weight is set at off the top of my head.
I wouldn't call myself an audiophile, but I'd say I'm pickier than the average consumer. I waited a long time to get my B&W speakers, only to now have a dent on the corner of one of them because the stupid cat knocked it over. Now my brother-in-law, he's got a VPI player, 10x more than what I'd spend. But he makes a living as a jazz musician.
The floor joists were 6” to 8” oak logs, with the bark still on them
That's crazy. Mine are your regular 2x8, which I sistered a few of them up to repair some old water damage. At the other end of my house was an addition off the kitchen which I'd estimate was built in the 50s. I had to rebuild that room almost from scratch (actually that would've been easier). Half the joists were cracked or broken from termite damage and the foundation had sunk a bit, which I jacked up the room 2". Nevermind the fact there was a beheaded clown under the floor and no vapor barrier over the dirt.
I did come up with an unusual idea, not sure if it'd work. I'd have a board with a magnet on the bottom at each corner. There would be a pillar at each corner to act as a guide to keep the board in place. These pillars would then be attached onto another board with 4 magnets on the top, opposite of the other board so they repel. The idea is a magnetically suspended shelf. No idea how strong the magnets would be or how stable it would be, but it sure would look neat!