Ok I did some research and according to three different parts books, M1 motors came with a 13 front sprocket.
M01- 12 or 13 front- 20mph & 25mph versions.
M02- 13 front
All had either a 28 or 40 rear sprocket. No refference to any sizes in between. My rear does says "Z32" which is typical on any Italian sprocket.
I did find it interesting that there was a 7 spoke mag wheel option. Same sprocket sizes as wire spoke too. I have no doubts that they were also 16s and probably the exact same wheels thats on this other Italian bike: