Mocked up a model of a limit switch, made a matching cutout for differencing, and used that to figure out where I'm going to put them.

I'm going to put a bead on the upper push-rod lines so that when they retract fully the bead hits the pulley and the limit switch is actuated.

Unfortunately the best spot also means reprinting the top corners which are firmly glued on.

I was hoping to get away with printing another part to add to the existing top corners, but that put the switches in a real ugly spot.  

This is nicer.  Reprinting.