Hi Ron, I thought you were trying to stay away from a stove needing electricity??
If the stoker was maintained well, then yes it could last another 20 years, the fan motors and stoker mechanism will eventually need repair or replacement, or allready have.
A stoker's fire will go out within an hour without electricity. If the fire goes out, and the electricity comes back on, it will start feeding coal to a non-existant fire, dumping good coal into the ash pan. A real mess. So if you have frequent power outages, and want something that is reliable all day long, I'd stay with a gravity feed stove.
Either Alaska or Hitzer come to mine.