Kenwood 500 turntable arm set up.

Here ya go!

https://www.etsy.com/listing/769507640/kenwood-kd-500-kd-550-tone-arm-panel

I take the old arm board to a plastic fabricator in town and have a new one cut, in plex, with no center hole but the screw holes on the perimeter like the original board, usually in half inch scrap stock.

I then take the board home, bolt it to the table and measure to the center of the arm hole, and then take it back to the fabricator and have them drill the arm hole around the marked center. Last one I did cost $28. Good luck  should be a nice rig when you are done.

@reched viridian is suggesting a very good idea, but I would expend on the Materials being used to produce the TA's Base Board.

Start with what is quite cost effective of which one option is already made known.

A Newplast Modellers Putty can also be added to the Underside of the Base Board material to substantially improve on the Damping Properties.

The Better the Damping for the mounting of the TA, the better the Cartridge will be catered for, as the local energies that are present, will have their Amplitude reduced or improved as a management.

The synergy that really impresses between the combination of materials will be discovered for one being quite unimaged for the valuable impression made.