Koonl, get some enamel paint (the type that you use for scale model painting) and use a brush to fill the lettering in. Build it up in layers so it dries quickly bu adding just a small amount at a time. You can use a hair dryer to speed the drying up if you like.

Just out of curiosity, it isnt an old set of Tour Action Reg 588's with the square grooves is it? I just ask because I recently refurbished a set of those.

D.