So far the hull has gone together very well and I've applied the zimmerit using Milliput. I did this by mixing some Milliput together and leaving it for 20 minutes or so, then I rolled it flat on a small sheet of glass (with a very small amount of petroleum jelly to stop it sticking).
I applied the Milliput to the hull sides and used the Modelkasten Zimmerit Roller set for the pattern (Hint: get the Trumpeter zimmerit roller set for half the price...D'OH!) and here's the result;

I'm quite pleased with it! :o)