Does anyone know the size of the small o-rings used on the VPI anti-skate devices? What type of finish is on the VPI VTA bases (silver powder coated)?

I would like to add a 2nd tonearm to my TNT 6 turntable. In the old forum, there was someone who fabricated a 2nd tonearm base (a la VPi Avenger) that was secured around the left rear tower. Unfortunately I didn't save the post. Has anyone else done this or have pictures of how this was done? Thanks in advance for any information you can share.