I checked my stash of the non-modular AD20 boards and didn't see any with a green dot. I'm also not aware of another use besides the 691-PCB1-012 with the red dot for a diesel's ditch lights, and the 610-8056-200 with the white dot for the wireless tether and back-up light/coupler.
These non-modular boards were only in use for a limited time -- basically around late 1997 -- before changing to the modular form of the board in 1998.
There is another part number associated with these boards, 610-8232-110, but it references back to the 691-PCB1-012. The 6-18232 Soo Line SD-60 may be the only diesel to use non-modular board, the 610-8232-110 and/or the 691-PCB1-012.
And the two Hudsons from late 1997, the 6-18056 NYC with the Vanderbilt Tender and the 6-18062 Santa Fe Warhorse, were I think the only two that used the non-modular AD20 steam board.
Lastly, I've had a heck of a time getting working non-modular steam AD20 boards from Lionel. Not sure if they were defective or just never programmed (although they did have a white dot) but they were completely DOA, just like your green dot boards.
Sorry I can't help further, but would love an update if you learn the answer.
TRW
