Just to close out this thread and the restoration, I was finally able to get smoke out of the engine and have attached a short video of it running. It's a little hard to see, but I think you can make out the puffs of smoke coming from the stack. I have an original style pellet type smoke element installed and am using smoke pellets (great old-time smell), although a couple drops of liquid smoke also work.
The solution was to install a bridge rectifier (a diode would also probably work) in the line going to the motor, which reduced only the voltage going to the motor (but not the smoke element or headlight) for a given track voltage input. Therefore, in order to get the train to the same speed as before, more voltage has to be applied through track power and the higher voltage was enough to overcome the resistance in the smoke element and get it to work and also brighten the headlight, while at the same time keeping the engine at a reasonable speed that would not throw it off the track in the corners.
The whistling tender also works very well now (although my seemingly disinterested assistant forgot to press the button during the video).
All in all this was a very rewarding project and I certainly learned a lot about post-war locomotives and can't wait to get started on a new one. Thanks for everyone's input.
