This is the model in the SP range that replaced the Minor 2. The engine and boiler are similar to the MM2 but with a blue painted frame. The main differences being a different base, base mounted chimney and chrome sided firebox (standard on most of the SP range),
It is an overtype engine with everything mounted on top of the 1 3/4" diam x 4 1/2" boiler, including the 5/16" diam x 11/16" stroke cylinder, 1/4" safety valve and 2" diam spoked mazac flywheel. There is a standard Mamod water level sight "glass" in one end of the boiler. It should have a solid fuel tablet burner but that is missing.
The paintwork appears to be original and is in reasonably good condition.