I've never carved one, but if you make a blank up with redwood, cover it with mastic, exacto knife carve the letters out, then sandblast, then paint the lettering gold. that is a easy way of doing it.
There is a sign maker in Scituate Ma. whos name escapes me, I will try to find it........anyway he used to have classes on sign making/carving! I had thought of taking one but never got around to it. I will try to find the name.....he has a website also!