Your guesses as to what this rare MV Agusta 175 might be and why it's unusual were excellent, and most of you deduced that it is a motorcycle with some kind of automatic transmission, hence the obvious lack of any kind gear change pedal on the right side of the machine where you'd normally expect it to be.
This is what was officially named by MV a "Motoleggera MV 175cc 4 tempi, con cambio idraulico progressivo (Licenza Idrobad), but for short the 175 Idrobad. It features a hydraulic transmission unit, designed by Sig. Badalini, so has no gearbox (so no pedal). The infinitely variable hydraulic transmission is controlled by the left hand twistgrip, whose cables run down into the motor not unlike those of an MV Pullman - in fact the handlebar cable mechanism looks similar at a glance. This Idrodad features a small button also on the left hand twist grip that allows the bar to be pulled in, and kept in, as a sort of neutral, handy for sitting at traffic lights and so on. At its simplest (it's not simple, it's complicated!!) the Badalini transmission used a hydraulic pump and hydraulic motor, both of a swash plate type - a ring of pistons is actuated by an inclined disc to give the variable part of the drive - like a belt on a cone in a modern CVT system I guess.
A special prototype of a modified 175 CS Sport had appeared on MV's stand at the 1954 Milan Show, and there's a photo of this bike in Mick Walker's book on MV Agusta (see above). The bike in this photo looks exactly, and I mean exactly like the bike I rode last week, and photographed. Another strong link to this prototype show bike is that the bike I rode has a lacquered fuel tank - MV didn't lacquer their tanks on these models, so it was probable it was done for a special purpose, like putting the bike on show.
I think it's one and the same bike, which makes this rare bike even more special, especially as it is in superb, original and conserved and UNRESTORED condition, which is how it should be left.
Watch a small video we made here on You Tube which will help to explain how it works.
There'll be a full feature on this very special motorcycle in Issue FIVE of the magazine.
Thanks as always to Dorian for making this very special MV Agusta experience possible.