Personally if I had to make these and , big AND here, in this quantity I'd setup on a 4th axis and using a tailstock to support a mounting plate mill enough out to cut up into as many pieces as possible.

The flat parts can be done with normal milling cutters either lying flat or stood up and using woodruff cutters.

The curves sections which as causing all the problems could be cut with an old end mill or router cutter [ more later ] with one flute ground back for clearance and the cutting flute ground for the radius needed.

The cutter could be ground to a CAD generated cardboard template as these curves are just clearance profiles and not critical to microns. Commercial ones are often die cast.

The reason I mentioned router cutters is that they are usually straight flute and grinding a profile into a straight flute is far easier than trying to follow the helix on an end mill.

I'm betting that grinding a couple of cutters is far quicker than drawing and coding the same part plus the time saved over one pass as opposed to many small step passes makes this a dead certainty.

All the passes can either be run manually or under CNC but the code for the CNC will be just power feed type passes.

3D CAD / CAM has is place but often and especially when quantity is involved a couple of jigs and special tools will be more cost effective as regards time and cash.