Lot of force on that for sure!! As designed the top of the head dovetail will go to the top of the column dove tails... I think I measured 22 inches from the table to the nose on the drawings.
If needed to I will mill a solid block of steel to replace the 3/8 part. I bolted it for now in case I need to modify it.
BTW milling cast iron is dirty and nasty! LOL not my favorite!
I got all my metal yesterday so I will be making parts the next couple of days.