The pre war burman gearbox is identical to the 1935/36 Ariel gearbox, the main shaft is also identical, in 35/36 the Ariels had the Cush rubbers in the clutch same as the A Vincent's. Even in the Burman catalogue, under the part number for the shaft, it states ....as fitted to Vincent and Ariel. I have the original gearbox from my 1936 Meteor and an original Ariel 1936 Red Hunter, same gearbox, shaft and clutch is same except for the duplex on the A. I will post details when I can. I am aware of a complete gearbox that I might be able to get my hands on in the not to distant future