While looking for something else I just discovered that mow parts sells 3/4" cotter pins.
https://mowpartsoz.com.au/collectio...clutch-cotter-pin?variant=38511663218839

So somewhere out there is a 3/4" clutch half that uses a cotter pin. Whether it's factory or aftermarket, who knows.

Last edited by looktall; 2 hours ago.