Waterpump Fixed
I have a friend who is a whizz with a grinder so I popped over with my 'issues'. The pulley was ground down with the grinder along with the bit between the nuts and the pump casting. It was all done in a moment and then, within a blinking of an eye, the water pump was installed and the engine was running.
The pulley no longer catches on the nuts and I expect this pump to last longer than the others (I have receipts from the previous owner and their water pump excitement!)