I have two Rock Island E7A's from around 2008. I recently installed RailPro and determined the following on the forward light board:
White wire Fireman's side is the bottom light
Yellow wire Fireman's side is the COMMON
Yellow wire Engineer's side is the top light
Blue wire Engineer's side are the number boards.
I used 470 Ohm 1/2 watt 5% resistors on the top and bottom lights and 1000 Ohm 1/2 watt 5% on the number boards