Looking for Numberboards for GP9

Decal paper will work. Reverse the print.

Scott Smith

does it matter that they need to be lighted?

Decal paper can be clear with black letters, they light just fine.  I printed some on transparency paper and installed them in an engine, they lit and looked like the originals.

I used a label maker, white tape black numbers.

I know that on more current-generation diesels today could be either way, but chronologically, on earlier-generation locomotives like his model, I believe the backgrounds were black and the numbers white/clear so that the numbers themselves illuminate instead of the background.  I know that some Geeps today have white backgrounds with black numbers but AFAIK that is a more current development.

Based on the cab number he provided, it's likely the Boston & Maine GP7 from around 1997 or so (#1558 shown below but they offered multiple cab # on the same model & paint scheme), and the model's number boards definitely have a black background with clear numbers:

You can print them clear on black on the transparency film as well.  I did them black on clear and used a white paper behind them for a background.