Interesting, i can see why you are having a problem finding images of the mechanism. I have 4 different images (from 4 different Swordfish) of the right hand side of the cockpit, and none of them show a wheel type mechanism.
Is it possible a different mechanism was fitted on most Swordfish, and/or retrofitted?
There are relatively small release levers in the Albacore, Skua and Barracuda (all port side) for deploying the arrestor hook. The drag of the arrestor cable was supposed to force the hook to return to the secured position (I think).
Which manual and what date is the mechanism diagram from?
edit: corrected location of Albacore arrestor release lever