Hi Rudy,
I have a low tension RH engine probably the same , pretty sure it?s an AP3 (24? flywheels)with a Bosch Magneto. From memory the engine number is stamped on the mag too. Another member in our club has a good original unrestored engine and it?s fitted with the same Bosch magneto too.
They also had a rotary mag and Wico EK versions of these engines too in later years.
My engine is currently all pulled to bits ( how I got it) and has a cracked flywheel so if anyone has a spare 6 spoke 24? Ruston flywheel in their junk pile I would be most interested.
Cheers Justin