"Heatalator" hasn't changed much in 40 years. The units still sell very well. Any good contractor supply has anything (new or replacment parts)you could need. The fireback is very thin for serious woodburning so a cast iron fireback is a good idea. The "smokeshelf" (flue control) is not at all a good design. Much smoke can be aleviated by modifying the draft for your purpose. The motor and squirrl cage are a standard product available from any good mill supply.