a couple 2x10’s would hold it but you need to think about the length of the chainfall/lifting assembly as a whole because you quickly run our of head height. Chainfall has a min length where it will lift etc.. Also, if its been 1” off center for the last how many years it will prob work just fine that way for the next 20. I would want to fix that too but would prob leave the mounts and find a way to make them work/rotate in place. 1” at the tip of the shaft would be a small change at the mount locations. No way to get those mounts moving?