One thought, with the advancements in LED technology, instead of 'adding' red LED strips, you may consider RBG LED replacement of the GI bulbs.
Use the original game code to run them in full on white mode, and use the P-Roc code to use multi color modes. You may have to design some small interface so that 'on' = 'RGB all ON' (AKA: White) as a default so there is no code changes needed for the pinmame code.