I’ve worked in manufacturing plants for more years than I like to share, generally speaking, if it’s cracked and you weld , it will crack in the same spot or near it. Putting heat into it from welding, weakens the material, Jimmy didn’t elaborate, but I would have to guess they welded the crack shut, THEN put a patch of metal on top to strengthen the area… That IS how I would do it for a customer…..
CR