I wouldn't be surprised if someone already thought of this but I made a spot polishing tool out of a leg leveler and some felt 'magic sliders' while repairing an area under a pop bumper on my neighbors Williams Super Flite. I should also note prior that I cleared the playfield with Shopline clearcoat.
The leg leveler worked great as it fit in my drill and the pad was able to flex against the playfield when it spinned. The felt sliders normally go on the bottom of chair feet to protect your floor from scratches so they have a microfiber type surface. I loaded up the 3 pads with Novus #2 at first, discarded them after a few runs and switched up new pads and then proceed to buff with Meguiar's Scratch X. Finished with some carnauba wax and I was back in business.
Save your wrists from exhaustion and give this a try