Without wanting to railroad this thread (i was just about to post a very similar one!) i think i'm in much the same boat with my Jurassic Park.  From what i understand Data East used very similar stuff to Diamond Coat, but with another trade name - please correct me if i'm wrong.  It looks to me as though there is the mylar around the slingshots (see pic) and then pretty much on top of that over the whole playfield (some pics of joins).  So it sounds as though it shouldn't be too difficult (with some care and patience) for me to also remove the mylar and give everything a good Novus 2 and wax and i should get some shine happening on the playfield?