Sooner or later in their lives, all bikes will generally get some type of unique or identifying mark or feature. For some it might be nothing more than a scratch or decal, for others the frame might be custom-built for the rider or perhaps the owner has chosen a few select components. This particular bike was the personal bike of builder, and it was used as both a test vehicle as well as a rolling calling card that showed the variety of solutions that he could build on customer's bikes. It was built in 1947 in Parma, Italy, by a builder/shop owner by the name Soncini.
The bike was built as a sport bike. It has brass mudguards, an indexed Lucchini derailleur, custom handlebars, wire matrix chainguard, 4 pivot brakes, internal brake routing, Campagnolo quick-release axles fitted to all-alloy SIAMT hubs, alloy Fiamme rims. Apart from the tyres, the bike is completely original. The rear vertical drop-outs were custom-made for the frame. The derailleur lever just below the saddle has four notches which accurately index the shifting.