I think you are on the right track. I know that just having the suspension set correctly can make a world of difference. These LP12's require a very delicate balance on the suspension to sound their best. You can add a number of upgrades, but if not dialed in correctly, the money is wasted. Again I suggest Rick only because I know first hand his expertise in reviving "out of tune" tables.
Best wishes
Theo
Best wishes
Theo