I looked up on Youtube long ago how to paint raised letters. It's pretty easy. you take a dowel or square stick, and attach a couple of layers of absorbent cloth (not fuzzy, relatively flat), pour a little paint in a pan, and dab the end of the dabber into it, and dab it on lightly. It is extremely effective and fast. A brayer is also good if the casting is of good quality, and the letters all wound up being the same height (usually) damage to the letters sometimes makes that a touch up area.