You can buy a new shaft with a handle attached - drill out the aluminium rivet head and drive the rivet out and knock out the broken wood from the head of the fork.
Insert new handle - drill 6mm hole through wood for the new (supplied) rivet - insert it and hammer down - finished.
I did one today - shaft from Garden Centre (bit expensive at £8) it took 10 mins.
Peccavi
June 2009