NSE is an organization "dedicated to the preservation of the history of N Scale Model Railroading, and the railroads they represent". And apparently part of what they do is release N scale models - some simply being custom repaints of other manufacturers' models, and others (like this one) being full-blown custom projects.
Here's what NSE has to say about their snow melter -
Needing to keep the track and switches clear of snow and ice, the Pennsy and their maintenance staff had to come up with a solution. So they did! They combined an old caboose frame with a flat car, an old aircraft type engine, heater elements and some duct work into a snow remover and ice melter. Our model was produced by Masterpiece Models, Micro-Trains Line, GHP, and with finishing touches by Dean Daughenbaugh and Fred Hoxsie. Our model arrives fully assembled and ready for the modeler to apply the windows if they wish.