The Seven Workshop lists the knob for the three speed gearbox
https://www.theaustinsevenworkshop.com/p...ob-3-speed
And David Cochrane lists both. It seems to suggest the the four speed is bigger than the three speed
https://www.theaustinsevenworkshop.com/p...ob-3-speed
And David Cochrane lists both. It seems to suggest the the four speed is bigger than the three speed