Jim,
Given the size of the letters, I suggest you paint them. Paint a broad gold background then apply a frisket mask of the letters. Spray the color, remove the frisket, then outline the letters using a large-size Rapidograph pen, Rapidograph black ink and a straightedge raised off the surface with cork backing or layers of masking tape, so the ink doesn't wick under it. You may need to use a little drafting powder just as when you apply ink lines. If you goof, Rapidograph ink is easy to remove with alcohol. Overspray with a clear coat to fix the ink into the finish. That's how I painted the AMA and my number on my T-Bird wing.
Mark Gerber