So Phil, before You put the new weight on the arm here are a few improvements that will make an allready good tt really impressive and on par with esoterica with ridicoulus pricetags.
The armboard, if a mk1 this is wood and all is well, what need to be done is to replace the tiny woodscrews that attach the armboard to chassie from underneat with M3 bolts and nuts.
Drill holes through the board and recess bolts from above and it will still look nice. This improves lf definition. The armpillar is also
attached to board with same tiny screws and rubber grommets.
Remove rubber and drill holes for M3 bolts. Tighten all those bolts realy hard, this works wonders both for lf deinition and hf resolution. If a mk2 the armboard is made of plastic, remove and use as a template to make a solid wood board, oak or birch works well.
It´s also worthwile to fill the innerplatter with polyurethane potting compound, removes all ringing tendencies from platter assembly. ( good ventilation required )
Happy drilling!