The purple is the machining allowances that were added.
These machining allowances are toggled off (suppressed) when the 2D drawings are made in Solidworks.
I think I decided to cast the ends solid, and then machine out the slots to an accurate size.
This design was much cleaner than the 1st attempt.
Eccentric.
I basically just made up the approach to take as I went.
There may be far better methods, but I make it up as I go, since generally these are first time shapes.