Crank/damper pulley woodruff key

I honestly think this is your best chance of long term repair- it has gap filling properties and will hopefully solve your issue.

Thanks, appreciated.
Not a big job to remove the damper and bung some adhesive on

and put it back with an air gun, it will be much tighter than your piece of scaffold tube, which was the cause of your problem in the first place

Couldn't have been the cause as this is the first time I used extended bar approach!
Tbh pretty sure damage was from the result of under-tightening as at the time of doing original cam belt job I had no way of locking the crank. Have since bought the ridiculously over-priced locking tool from difflock, that said great service and next day delivery