Mark,
These are also available with a replacement LED instead of an incandescent bulb Unfortunately,I can't recall where I ot mine - either a Google search or someone else on the forum will be able to tell you. The LED's are plenty bringht enough as well. There are also some real cool replacement LED square colored lamps available as well, with a cover under which you can insert a transparent label with its function. Ironflight has these on his RV-8 and they really work well, and IIRC, the complete lamp assembly was cheaper than the bulb replacement, and I recall giving Dennis Glaeser a small panel with 3/4 in it. If you're interested ad can't find it from Ironflight or Google, post here and we'll find them for you.
AllanC in Mongolia