Bush MB60, TR82, VTR103 and other variants

[Robert Darwent]

That is exactly what I was thinking of. The pressure is from the inside of the spring clip.
The clip stops the screwdriver from getting close to the boss. Any marks will be made on the inside of the boss on the edge and will be low risk as the clip will stop a crack forming.

It is true that the "clip stops the screwdriver from getting close to the boss" but equally the clip supports the plastic of the shaft whilst you are removing it with a cord as well. With a cord/plunger the majority of the pressure applied is straight upwards and you are using the entire diameter of the knob to distribute that pressure evenly. It's not the same situation when using two screwdrivers, you have two contact points focussing the pressure. One slip with either screwdriver, which is quite likely, and the pressure is suddenly one sided on the shaft.

In any event, to my way of thinking it's got to be far simpler and easier to slip a cord under the knob from the front of a complete set, than to take the back off and remove chassis screws in order to gain limited access with a pair of screwdrivers. Screwdrivers that when they slip could damage the metal dial, tuning capacitor or some other internal component. But each to his own preferred method of course.

Regards