Contact Paul at little-cars.com, he has Bare Metal decal paper for ink jet printing, which is good stuff. It's best to print on white to get correct colour density, if you print on clear film you will still need a white backing. Use a heavy ink setting, let it dry completely, then spray with Klear or Micro liquid decal film. The instructions say you can brush on the over coat, but if you do you will risk smudging the ink.
I've been thinking about drawing up some artwork for 74 Sqdn machines as there seems to be a lot of interest in it, maybe after Telford.
peebeep