When using prefabricated Zimmerit, I always use Cavalier. As it is molded in Resin and easy to work with..especially on Panzer IV's. As for the King Tiger Porshe Turret, I am completing my own right now. I applied the Zimmerit with Tamiya's Polyester Putty and #7 Zimmerit Apllicator. I have to tell ya, the results using Tamiya's Polyester Putty is awesome. I'll never use Epoxy again.
When you refer to mask, do u mean to mask to make chipped paint, or mask to create a camo pattern?