I've never milled one. I have used a dovetail mount from Springer Precision or CGW and I have drilled and tapped the slide for a short piece of rail and used a tube type Ultradot on the kadet. That is my favorite setup for the Kadet since the optics are so good on the tube type sight. But it is large and heavy compared to the reflex type red dot like a Burris Fast Fire 3 or Holosun 507C.
Due to the curvature and width of the slide, you may have to mill it and tap for an adapter plate, and then mount the red dot of your choice to the adapter plate.
No matter how you do it, you will love it.

Joe