From the same builder as the "Sub Nigel" Hudswell Clarke I've currently got in, this engine is a model of one of their industrial 2' 6" gauge 0-6-0 tank engines.
Silver-soldered superheated copper boiler, working pressure 100psi. Feed by twin injectors with handpump at rear of cab. Gunmetal cylinders with slide valves actuated by Walschaert's gear with pole reverser in cab. Mechanical lubricator.
Probably even grottier paint than the "Sub Nigel", however another engine that goes well and worthy of a decent overhaul. There's a clip of it running in the sunshine yesterday afternoon here.
Length 38 inches
Width 14 inches
Height 23 inches
Weight 160 pounds