"Holt power unit."

This model, in 1/48 scale, is of a gasoline-powered, four-cylinder Holt engine and radiator set up on an imaginary skids arrangement. It will be used to power a ten-stamp mill on my O scale layout. It is completely scratch-built of styrene, acrylic and metal. The valves are pins and the valve springs are Kadee HO coupler springs. It took a solid week, but was fun to build.