Concaved i think mate. It has Mylar or a protector on it too.
If it has mylar, then it would be a big job removing it to get to the inserts. However, if it is contact, then it MAY come off easy. If it is annoying you and you don't want to take any risks - I'm thinking one of those playfield protectors would work to alleviate the concaved inserts for now.
