I do feel your pain, brother. At this point, I'm very thankful that I still can hear and enjoy music, period. Fortunately, the brain can perform wonderous compensations, and when I turn up the gain in the right channel mono preamp, the soundstage is much better. I also find that listening at somewhat lower volumes actually helps with most kinds of music except for large-scale orchestral works.
Thanks for your Marantz suggestion. I'll look into it. I've pretty much decided that if I keep my tube gear, I'll get a Schitt Loki. If I sell the tube gear, I'll be much more likely to invest in something like a suitable Luxman or Accuphase and be done with it.