Cannon Uni-Troll 6 Issue

[YodaMage]

So I am using two old (but good condition) 48" Unitroll 6's and have an issue with one of them. The internal shaft (not with the crank, but rather the one with the tensioner on it) is stripped. It popped off while bringing up a weight (run away!!!), so I had to manually turn the spool to bring the weight up. Can this shaft be had anywhere?

If I am looking at new riggers, what cannon unit sits on the same mount as these so I don't have to drill more holes and mount new plates.