This Christmas I found a 6-21955 Rio Grande passenger set under the tree. This set comes with a powered F3 A and a dummy A. I rebuilt the dummy as a powered A using the set shell and front truck. I also used an on-hand MPC single-motor F3 frame (was black so I rattle-canned it silver), a TMCC electronic E unit, and a GP power truck and motor. I also used a GP silver colored power truck frame from which I cut the pilot and steps. If you look closely the gap between the engine and first car is wider than normal because of the long GP coupler shank. Some day I'll pick up a proper silver F3 rear power truck frame to address that fault. Meanwhile I added an excellent running Rio Grande F3 to the Plywood Empire Route's iron horse stable.
Lew
BTW, the pic on the wall is of the prototype Royal Gorge c.1962.
That day power was a pair of PA-1s.
Dad took that pic from the Dome.