Quoted from metahugh:I could have taken better pics of the cracks on the inserts but you get what I mean.
Those are not cracks, that is an effect called "Crazing".
As every playfield restorer will tell you, the crazing is invisible until you spray the new clearcoat on the playfield.
That Crazing pattern is actually inside of the insert plastic, it's not on the top, it's not anything that could have been sanded out.
Old games used to have a cloudy clearcoat called "DiamondPlate". The cloudyness hid the crazing.
When you remove the old clearcoat and redo it with a modern clearcoat, that crazing often becomes visible.
New games have that amazing, super clear factory clearcoat that really makes the colors pop. At the same time, that clarity allows the Crazing to be seen.
It's totally normal.
Here is an old High Speed with brand new clearcoat. The crazing is now reveled:
7766c78cc671413f284e85d9d8143b8f (resized).jpg