For what it's worth, I'll post the fix for anyone else who may search for this topic.

I finally got around to opening up the engine today to have a look. When I inspected the unit and manually moved the wheels, I noticed that the smoke lever arm never appeared to move. Somehow the lever arm was not in the proper location and not pushing on the piston to make the unit chuff smoke. I suspect the unit was dropped or jostled over the last 25 years along the way. The unit was smoking well enough to amaze my 3 year old! Thanks everyone for your opinions and advice!