New brake switch
The brake switch have finally given up and my brake lights have started sticking on intermittently. The brake switch is the original one and was pretty rusty, so it wasn't a surprise it had stopped functioning.
Taking the switch off is simple and a quick inspection showed the problem was down to the small piston sticking. The new switch came complete with wires soldered on and bullet connectors, so it was a quick fix to swap the switches out and adjust the setting.