I've taken photos of the dimple damage, but the glare obscured them. I took several videos that the problem is highlighted. I'll see how I go with uploading it. It is quite large.

I recently examined a "restored" ST TNG playfield installed in a game. It was clearly too thick, and it had divots / dimples all over it. I assume the same wood is used on all ST TNG games - original playfield - just badly cleared. The divot / dimples were caused by the ball impacting to poor clearcoat.