Hi Vicki,
Thanks for asking that question. My bonnet hinge is the same where the bolt pivoted into the body at the very back of the bonnet has rusted and snapped, leaving the threaded part of the bolt inside the hole.
I've bought 2 replacement hinges and have been looking into replacing the 2. When the car has been in for service, the garage has always been frightened to give a quote saying that it will be very expensive as they would need to remove the window wiper motors and the dashboard in order to get access. I keep meaning to take the car down to get a proper quotation, but for the moment, I've increased the tension on the hinge where I've managed to position it in a small recess that the bolt screws into.
Hope this helps, but if you've got yours sorted, perhaps you can let me know?
All the best.
DJD, August 2014