Second hand Back to Stationary engines

Small scratch-built twin cylinder engine - stock code 8024

£65.00
An interesting small vertical twin engine, apparently scratch-built. Can't quite decide whether we'd describe it as "piston valve", "sleeve valve" or "uniflow" - I'm sure there will be some expert reading who will cast light on its origins.

Turns over freely, missing (we assume) a sump plate or base.
 
length/inches 3.5
width/inches 2
height/inches 4
weight/kg 0.5