Steverino,
When you say "it continuously reverses position" is it on the track or alligator clipped to a transformer? The answer to that will help narrow this down. Clip a lead directly to a shoe and the other to frame ground (while holding the engine right side up) and see if you have the same problem.
Bending the shoes is easy with a rather large slotted screwdriver. They'll bend pretty easily. Don't bend the rear shoe too drastically as it will then catch on your switches. Replacing them, though, is a pretty simple procedure. A flashlight and a slotted screwdriver is all you'll need. And you don't need to take anything apart.
