As with many of my components these are fabricated from solid bar. The three pictures shown below are starting from a raw bar, removing the excess and shaping then the finished product.
This has probably been one of the most labour intensive of all the parts. Now that they are done, with the exception of polishing (which is no mean feat), I am very happy to move on to the thumb wheel and pressure pad.
Update: A modification has been made for ergonomic purposes. An additional chamfer has been added in case there is any contact with fingers or knuckles.