Wow, looks like some work! Defiantly need to get the tup smoothed up or it will just eat your seals. Not sure how much you may be able to take it down but you may be able to make the mate lager to accommodate the loss. When I rebuilt my steam hammer we took a 1/4" overall off the piston rod, packing did the rest. Brazing cast should be fine, some use splints to reinforce the area, try and be gentle with her...