I've ordered a drop-down edge guide and knew i would need an extension for the lift lever. I bored out a suitable piece of steel rod to fit over the existing shaft and tapped it for a couple of grub screws. So far so good. My intention was to refit the original rod/knob assembly by tapping a hole in the end of the extension but then I found it's an odd-size (to me) thread - M6x0.7. The closest I had was 0.75 pitch! I was faced with making a new shaft/knob, not difficult but more work. Then last