Update on this engine. I got a call from The Motor Doctor yesterday that my engine is repaired and ready to ship. They rewound the armature and gave me 20% more turns for greater pulling power. And.....they added traction tires to two wheels. I asked Albert what the armature looked like when he had it apart and whether the added weight burned out the wiring. Turns out, he found some bad, loose wraps inside and one of more apparently mechanically broke. Good to know.
When I get it back I'll report how it runs.
Roger