These are the specs:
Type: HVO-98-300 by Wiggers Germany.
Stand and flywheel are castings, other parts fabricated from plans delivered bij the same company.
Bore of the displacer cylinder: 43mm
Displacer: 41mm
Stroke: 32mm
Bore of the working cylinder: 22mm
Stroke: 32mm
Flywheel: 120mm
Total height: 300mm
This was my second build.
Funny about this one, both cilinders are oscillating.