This could happen on any clear coated playfield (CPR, Mirco, original factory NOS, any restored playfield, or any clear coated playfield). There are a lot of variables that can make this happen. It could be an adhesion issue, temperature causes expansion/contraction issues(extreme heat/cold), humidity, wood twisted/flexed, glue issues on the inserts, clear coat too thick, clear coat shrinkage, etc). The problem is that your dealing with an automotive type of clear that was made for vehicles. Clear coat on a playfield takes differently to the wood areas and the plastic (insert) areas. I do not blame CPR. I believe they ran these about 10 years ago. Most likely the issue is how the playfield was stored.