After purchasing my '74 MKIII 450 in 1976 from a dealer in London, who had 3 other secondhand 450 MKIII, 2 x 350 MKIII and 3 x 250 MKIII, as well as scrambler 450 and 250's, I visited Coburn & Hughes in Luton for spares and to pick the brains of the mechanics, before I emigrated to the IoM! At that time, in August 1976, C&H showroom was full of MKIII, Scrambler and Desmo machines that they were finding difficult to shift and the warranty work they were receiving on chrome, paintwork, electrics and engines was problematic. Many people weren't changing the oil frequently enough, or were 'lugging' the engine in too high a gear, as you could with a long stroke single. Why would you buy an Italian single, with a catalogue of faults, when for less money you could buy a reliable Japanese 4 cylinder, albeit with chromed disc brakes and nylon tyres!
My electronic ignition packed up, as I suspect many others did and with no workshop manual and no readily available spares I had to resort to building the EI box described in the 'Bike' magazine of the day that Bill Haylock and 'Another' devised and fitted to a 450MKIII. Mine worked well, as long as the lights weren't switched on, as that caused the fuse to blow! At the time, my electrickery skills were few and I had a boat booked from Liverpool to Douglas to catch. So, when I went to start my journey and after the repairs that I had made, the lights were turned 'ON' and the fuse blew again; I had to resort to the British Railways guards van. But, that is a whole different story!
C&H were "burnt" badly by the MKIII widecase singles. Why would C&H wish to compound their problems, with Spanish built machines, potentially harbouring more of the same problems, even though the Vento looks the part?
Have a Merry Xmas and Good Health for 2022 and beyond, Bill