Daniel, the 'rub-down' letters etc are what used to be used in design studios and so on. The most common types are 'Letraset' and 'Blick'. The character is fixed on the backing of translucent plastic material. The letters are positioned over the desired area, held flat, then the face of the tranlucent plastic is rubbed with a stylus (a blunt pencil, end of a paint brush shank or similar will do), pressing down on the letter on the opposite side of the plastic, which is then transfered to the surface of the object being lettered. For modelling purposes, they can be useful when normal, waterslide decals can't be obtained, but they can be fiddly, and sometimes impossible, over certain curves and shapes.
This type of lettering shouldn't be confused with 'dry transfers', which work in a similar fashion, but are applied differently. The big advantage of the latter? No silvering, and easy fixing - once you get used to the positioning!
It seems a quickbuild, I'll admit, but It's now been three weeks, working at least 4 hours per day, often more than 12 hours!
I'm trying not to rush it, but there are other things I need to get on with, so, the sooner it's done, the sooner I'm free!