Moped Army

Someone recently gave me this (what i think is a 70's model) moped. The key to the ignition switch is stamped "YAMAHA" which leads me to believe its a yamaha moped. It looks similar to an FS-1, but with small differences from the pictures I have seen. On the front of the moped there is a small plate with some tire pressure information and the the following stamped into it: "I2 I979" & "I8I53." I think the first number may stand for December, 1979. It was made in Italy. Its a 2 stroke ~50cc, pedal start engine with chain drive. Its in crappy condition; needs a bit of work and knowing the make, model, and year would be invaluable. Attached is a photo with the engine removed. Any information would be greatly appreciated.
-Seth