Here are some dwgs I had on file. Not sure where they
came from but they originated in June 2008.
They look like your style George.

The pictures are of Richards Sohn's cut down one rotor shaft.

The largest problem one would have installing this engine in a helicopter
is dealing with the severe torque pulses. A one rotor looks like a really
big 120 HP two cylinder engine in that it fires once per 360 degrees
of revolution. This will require a really large and soft rubber coupling
to get the torsional resonant frequency down below 2000 RPM idle.
Last picture.

Paul Lamar