Bought the proper studs to secure the Wilton vise to the drill table and drilled the remaining hole in the long leg of the step. Used dish detergent for lube as per tail stinger instructions for very similar procedures. The hole came out perfect this time. Installed the step back into the fuse fittings and matched drilled through them and out the back side of the fittings. Installed 3/16 junk hardware to test fit. It turned out great! I was concerned that the off center hole on the short leg would be an eyesore and it is not apparent viewing from the side.
Received the firewall bracket coordinates from Kevin and made a template on a piece of adhesive backed poster board. Cleaned all the primer from the diagonals where the brackets will be welded. Cleaned the layout dye off the six brackets with acetone.