Almost as old but not quite: In the late 80's or early 90's Scenery Unlimited had a run of custom painted IC FP7's to go with the IC passenger cars they had AM make. While the passenger cars were done by AM, the FP7's were not. It appears HO decals were used on the FP7's. I wound up buying the last two Don had and numbered them in an opening after IC's E8/9's.
And of course, like the GN, the IC never owned any FP7's, let alone any F-units, until as the ICG, the railroad inherited some ex-GM&O F3's.
Once AM did the E8's in 2001, the FP7's became superfluous, but they're too nice to part with and still make a guest appearance every now and then.
Rusty