Why not do your touch ups and take the playfield to an auto repair place and have them clear it?  You have fully stripped the top of the playfield so this wouldn't be a problem.

If you decide to do this make sure that you prepsol the playfield before you take it.  

Clearing the playfield will give it a nice shine and give you the results that I think your are looking for in this restro.

If it helps with your decision my HH had mylar on it when I got it, but there was a lot of lifting along the edges of the playfield window.  I have since removed the mylar and I'm planing on clearing it.