Drilling my Zbar??

My opinion, we have not seen the bell, but I believe that a machinist could machine the area and make a part to fit and then be welded in. They make specialty welding rod for cast iron. Or fill the area with that specialty rod and remachine the area and drill and tap a new hole. Pretty sure this can be done.
I would not go further with the way it is. I also would want to have eyes on another car like yours that is orginal, to see what else may be incorrect.