That is sad Tony.  Perhaps try the freeze spray method?  Seems that every different playfield/mylar combination behaves differently.

I remember doing my Meteor - mylar came off fine but the glue was a bastard.  Left some 'orange power' on to soak for 20 min and ALL the playfield paint went soft   Had to clean it up with shellite and get it repainted and clearcoated - looks great now 

good luck
Ian