The Pulley is attached to the shaft through a one way bearing which is keyed in to both the shaft & pulley. The shaft spins in bearings mounted into the disc supports. The Disc is bolted to a pair of spacers/supports which grip the shaft with a pair of grub screws. 2mm thrust bearings then go between the Bulkhead and the pulley, the pulley and the disc supports then finally the support on the other side of the disc and the second bulkhead.

I will get a pic up at some point if I can cos that reads back like a mess.