Quoted from Mvfvette1:
It's much more likely that the mylar was never put down. The lower mylar did not come factory installed, it simply came with the game and the buyer could choose whether to apply it or not. With these older games that did not have a clear coat on the playfield, it didn't take too many plays for the the black around the inserts to start wearing. This is especially true if it was a novice home owner, that didn't keep it clean and didn't change the balls too often, or ever. Judging by the very small amount of wear around the the spinning discs, I do believe this to be a true home use game. A few more pics of the correct areas would clear up the issue very quickly. In my opinion, this is a super nice game and the cosmetic flaws can be fixed pretty easily. Once that's done, this will be a beautiful, mostly original, low play game. I'd rather have this than an old pig with lipstick (beat up routed game with aftermarket playfield and cabinet decals). If I was the OP, I wouldn't give this one away.
The mylar for the lower playfield is in the envelope with the other original materials that came with the game.