Thanks, all. Not sure about what scheme, but since Normandy to Falaise was summer, probably no white-wash. I would imagine that most of however few of these things that were in western Europe were out of action by winter.
I used a pocket screwdriver for the zimm. Slow, but just the right size. I had to keep it a little wet, or else the putty started sticking a little. For the zimm I did with heat, I filed the soldering iron/hot knife tip to the same size and shape as the screwdriver blade. Getting the putty on and spread in an even thickness was the hardest part.
This is my first real attempt at zimm, primarily because I was a bit scared of ruining a good kit. What I did was pretty much a compilation of different methods I've seen here, mainly.
Edit: As far as references, I used a couple of build articles on Dragons KT Porsche with Zimm, and a couple of old Tiger books. I hope Dragon's zimm is pretty accurate.....