Another way to spot if a bike has been converted from 'A' spec is the battery carrier is different, and the LH sidepanel is retained by a plastic Dzus fastener. I don't know if this set-up would accomodate the ham-can airbox - I'd be interested to know if anyone has done this?
They also have a tall 2nd gear which really lets you know it's there when changing down - made worse by the 22T gearbox sprocket.
As already alluded to, it was all done to pass emissions regs, including the taller 2nd gear.
I believe the JPN reps were all MkIIAs?
One just went on UK ebay for an eye-watering fourteen thousand of our Great British Pounds - lordy!