How to square up an angle plate

[Sunset Machine]

My shaper won't stop until the saddle runs off the end of the leadscrew. It needs me.

The angle plate. If there's room, how about using a lathe to flycut it square? Bolt it down in place of the toolpost and rig up a cutter for the 4-jaw.
Here's one for the horizontal mills.

[PixMan]

Oh, that I could have the room for such things as a horizontal machining center. I would rule the world!