I wouldn't know a rotating hook shaft if it fell on my foot ... so which part is it??
Is it the long metal rod that runs from the far right of the machine, through the black part - and there is perhaps a 1/2" - 1" piece sticking out the other end of the black part (I know .. all these technical terms I'm using!). If so, that should be easy to find or make. I would remove it entirely and bring it to a machine shop - but make sure they know that it should be straight - not bent (or they may duplicate the problem).
Without knowing what is on the other end, or the exact diameter - it looks like a piece that my husband machines for the machines that we make. We make sowing machines - not sEwing machines - sOwing machines
