I've done two so far
https://pinside.com/pinball/forum/topic/polishing-up-a-silverball-mania/page/2#post-3927310
https://pinside.com/pinball/forum/topic/laser-ball-just-because-resto-mod#post-4705117
took lessons from here:
https://pinside.com/pinball/forum/topic/silhouette-cameo-pinball-restorers-club