Everyone—
Thanks so much for all your responses on keeping the smoke unit a pellet type, and replace the heating element or rewinding with new nichrome wire. I did find a number of suppliers of the replacement heating elements.
Just as a future reference for part numbers:
671-169 original wire wound heater
671-225 updated wire wound heater w/ ceramic
671-212 smoke heater liner (fiberglass?)
671-181 stack gasket fits on top of heater between die-cast engine stack.
Carl J