Part-built piston valve vertical engine

An interesting enclosed crankcase piston valve engine - I don't recognize the design or castings, I'm sure somebody will enlighten me. Work to date is good in the bottom end - crank looks nicely made and turns smoothly - but a cockup up top has seen a couple of drilled holes break out of the casting.

Height 8 inches
Bore/stroke 1 1/4 x 1 inch