Here's a lil mod I did for Clyde that wasn't too happy with a single key used to lock his open driveshaft. I turned a shouldered bung, pressed into the yoke and drilled and reamed for four dowel pins placed half into the shaft and half in the yoke. That oughta hold it from coming apart.
I make these to fit your original CV, or S&S Super E/G, Super B, Bendix, Mikuni and SU carbs. They measure 5 1/4 diameter x 3/1/8 total height and includes a 5" custom-sized K&N for your filtering pleasure. Mikuni & SU requires adapter bracket ($40). Please specify which style you want when ordering. See store for ordering info, or hit me up at firstname.lastname@example.org