Bosch corded lawn mower *needs repair* (Barnard's Green WR14)

Bosch mains lawn mower. A couple of weeks ago it made a horrible noise, so I dismantled it and as far as I can see, the motor is absolutely fine and the problem is with the rotor that the blade attaches to. See 2nd photo where screwdriver points to. I don't have the tools to dismantle any further so am offering it on Freegle. I have all the bits, it only takes 5 mins to reassemble.