Here is a tool I made to help swap the vise jaws on my milling machine:
I started with a part from a place I used to work at (the top in the photo)
Cut it apart (2nd in the photo)
Part it off at the end of the knurl. Bore the inside to fit my Allen wrench (will fit 5/16"-3/8") and press in a stub wrench. In tight spaces it works to turn an SHCS in or out. In my case it works well when changing vise jaws.
I have several of these available if anyone is interested (cut in two, ready to finish). Free, just send me a SASE.