you can see the shoulder on the right that needs to be removed. I started with a Dremel but finished with a small hand file.
Yea, don't use a Dremel. Took a couple of minutes with a box cutter razor blade. The plastic is very brittle, which makes it easy to shave, but also easy to f' up. I got mine super smooth & round with only vertical strokes with a razor blade.
this was my first attempt at the switch.
Those inserts look perfect! Where did you source them from?
Welcome to the RS Cruise Control Club!