John Emmett rebuilt it as a Le Mans car. No doubt he'll fill in the blanks himself when he sees this thread. Some of us saw it soon after completion at a PWMN gathering.
Interestingly Sam, 0687 does have the chassis brake pedal bracket that you were asking about earlier, rather than the brake pedal being on an extended clutch pedal shaft.
There were few M's built in Oxford after that one in October 1929, and I'm not sure when Abingdon got up to speed in 1930, but I would guess the accelerator pedal moved to the right and the transmission brake disappeared around that time.
I wonder what John Emmett did with the mudguards - I could maybe use them to create some Shinio look alike mudguards. How could I contact him through this website?