Thanks for info David. A friend had a military Bianchi single. It had a very low "marching" gear normally locked out but for parades.
Regarding electrics I remember seeing a wiring diagram for a Stornello. The normal three phase alternator used each raw phase individually. One provided spark via coil (possibly with redundant spark), a second with single phase rectification charged battery and a third provided AC headlight supply. Kept costs down I guess.
ETA: just checked my Italian hard back Colombo book which is possibly earlier than yours, printed around 1977 and running only to 343 pages. Cannot find any mention of your bike in it unfortunately.
As mentioned earlier the engine shape is nearest to a Lodola (1956-66) which came with 175cc ohc engine or pushrod 235cc, I had both. Wonder which valve operation yours has?
