Thought someone should post some photos so here's a Lionel GP9 in Wabash paint with the original coupler sitting behind an Atlas GP9 with Kadee coupler:
Here's the Atlas GP9:
And here's the Lionel GP9 before I repainted it and installed Kadees:
And after:
GP9 1912 was the only Seaboard GP9 to get their light green paint scheme. Warren Calloway provided me with a black and white photo of it in this scheme along with a black and white photo of it in the dark green scheme and you can see the difference in the shades, even in black and white. If there's a color photo of it in the light green scheme it hasn't been published yet.