For almost 4 years now I have lived with the fact the the gear knob rotates under use. It was just a push fit and over time it has got worse and worse. It a symmetrical knob, so it didn't affect the use, but I just got annoyed when the diagram on the top didn't match the gear gate.
So time to stop faffing about and get a new one. Here it is installed (with the original just below it) and while it is still a
push fit, under the aluminium collar are 3 grub screws to anchor it
solidly to the shaft. It also has an extra bonus of being larger and
just over an inch taller so gives more torque on the gear change.
I'll be able to test it properly on the Stilton Cheese run tomorrow.