Unaflow steam engine.

[Cascao]

[mklotz]

Very nice.

A brief description of how a uniflow engine operates and the advantages and disadvantages of the design would enhance your presentation considerably. A good starting place would be the Wikipedia article...

https://en.wikipedia.org/wiki/Uniflow_steam_engine

Uniflow provides no benefit at all if the engine is run on compressed air. That and the fact that they tend to run too fast on steam probably accounts for why one sees so few model uniflow engines.

Regardless, it's a beautiful model, skillfully machined and certainly worthy of a place of honor in the display case.