This is a simple engine using an old UK penny for the base. This example was customised by Phil using a shilling for the flywheel, instead of the normal turned brass one. The shilling is dated 1949 (my birth date). The penny is dated 1948. I also have an earlier version without the compressor (see here)
It has a tiny single acting oscillating cylinder, 1/8" bore x 1/8" stroke. The engine block is supported on two ornate brass pillars, one of which carries the steam feed. Exhaust is through a hole in the top of the block. The pillars are mounted on a 1948 UK penny, with the steam inlet out of sight underneath. The penny is supported on three brass feet. The crankshaft has a 1949 UK shilling fitted as a flywheel.
Unusually for Philcraft, the name is engraved on the engine block.