So, the '47 A7 was the first bolt on to the crankcase transmission approach. Later abandoned. The attached drawing makes it look like a standard 6 bolt transmission, loose roller bearings like the ones on my old Triumphs and Matchless'. Except for the double chain, (which I'm prepared to switch to a single) and the odd split ring supported backing plate. Getting an original will be tricky. So, despite my vow to keep it original, has anyone any experience or ideas where a more faithful unit may be gotten?