Steve, looking at what you assembled for no more money than you've stated, you put things in proper perspective. You spent your hard earned money on music.
I started collecting records when I was 13, most were ruined by my carelessness by the time I was a teen and I deeply regretted that. I spent the rest of my life caring for my records and today I can pull out some of those VERY old LP's (originally played on a Thorens with Ortofon arm) and they are still quiet and sound great. Have fun with it.
Frankly I would rather visit your home and have 6 thousand records to choose from and tube electronics, than some "super" hi fi rig where the owner has 50 audiophile titles (all boring) and no fun listening.
I am familiar with your turntable, arm and amps but not the Sansui or the speakers. So, I am really not qualified to advise you about an upgrade. You have done well so far, trust your own judgement and play all your music when making a decision. That's one of my main goals when working on my system. Make it as good as possible but I must be able to play everything I own and it sound good.
Lugnut (bless his soul) laughed out loud at my system because I would slap any title on the table and let it rip. The gang bought a $2.98 "Men at Work" LP and I played it without even cleaning it.
He thought that was great, and the funny thing is, it sounded very good.