Carl,
Just a thought mate but model aircraft decal sheets normally have (decal) print on them saying what type of kit it is and item no etc. e.g. a kit decal sheet by "HASEGAWA" would yield the H M S (reverse W). They are about 2mm for 1/48 kits but of course are normally in black decal. Perhaps you could paint over them once applied? If this could work for you - and I have no idea how you intend to use them - let me know and I can sort you out. I am not sure what Tommi has in mind but with tiny 2mm stencils to try and stipple over, it may leave them looking a bit ragged around the edges?
After the 'Ladybird' book story you sent me, it's the very least I could do to repay you .......................!!
Cheers Carl and good to see you at the Telford Nats the other week.
Gary