The 'Rospo' was a production racer built between 1956 and 1959 for the 'town to town' races popular in Italy at the time. It was sold as a road bike, hence the artificially large silencer, designed to make it look like a bigger bike. Anyone else think it looks like a trumpet with a mute? Also, notice that it has bicycle pedals, I'm not sure if this was so it could be classified as a moped, a bit like the bikes sold in Britain in the 70s.
The story behind the name 'Rospo' is interesting:
The unusual 'back-bone' design of the 50/T2/SS gave rise to its nickname which originated in the premises of Lina and Guido Borri at Via Mazzini 54 in Bologna; the Borris were formerly dealers for Italmoto but now Maserati. When they took delivery of the new model, Lina took one look at the it and exclaimed: "Ma cos'è questo brutto rospo? ("What is this ugly toad?"). From then on, the 50/T2/SS was nicknamed 'Rospo' (toad) and Guido even attached specially designed decals to his bikes depicting a toad 'ready to pounce'.
The rider is Beryl Swain, famous for being the first woman to compete on a solo bike at the Isle of Man TT. Soon after, Beryl had her International Race Licence (necessary for racing at the TT) withdrawn as the race was 'too dangerous for a woman'! Male riders being embarrased at being beaten by a woman is a more likely explanation.