The biggest problem you'll probably encounter is isolating the motor. Pick up for those old brass engines was all over the place. I don't have any direct experience with them, but I understand that many are designed so that one side of the polarity is picked up from the drivers while the other is from the tender, and everything else is dead... making pick up iffy overall.
The motor frame is sometimes part of the electrical path, and is mounted to the frame with screws, so there's no real way to break that circuit without creating other potential problems. I took one brass diesel apart and found that the worm gear was part of the electrical circuit! How the hell do you isolate that!?!
Let me know how it turns out... You're always welcome to bring it down for a test drive!
Lee
