i worked in a food plant everything was stainless. i had your problem many times. the best solution i came up with was to run and tap into every bolt...
better check your numbers. make shure that gen. has enough power to run the welder. i had the same idea and found out i would need a bigger gen. then...
i would get one of the old shafts tested to see what it is. maybe the shafts were to be the weak point for a reason. better to twist a shaft then to...