So we picked up a basement-dwelling black knight the other day. Heavy ball marks on it, but it'll make a nice player's machine. I'm trying to remove the upper playfield, and it seems to be glued down in one part. The back right of the playfield will not come off, and when I pull the upper playfield apart from the lower, I see what looks like strands of glue coming apart underneath. Is the playfield supposed to be glued down? If so, how are you supposed to remove it? If not, what am I missing? I removed the four big screws, and have undone all the connecting ramps, including the sides. Is there something else?