Just a quick note, I have now completed the rebuild of my 1930 Model 9 BT Gearbox and have posted photos and videos to the Club website in the technical articles section.
http://www.marston-sunbeam.org/technicalNotes/Model9GearboxRebuild.html (http://www.marston-sunbeam.org/technicalNotes/Model9GearboxRebuild.html)
Graham