I have a similar problem with the "bonnet hinge bolt fittings" on my bonnet support frame.
Basically the thread is completely gone on both sides. Which I discovered on the day I had invited several friends over to help me fit the bonnet.
No worries, I have a "rethreading tapping "kit. So I got to work on it this afternoon.
Unfortunately no matter what I tried, I could not make an impact on any side of the support frame.
Since I do not really fancy buying a new bonnet support frame, any suggestions?
Update.
I had used the imperial thread bolts supplied by SNG for this purpose. Other posts on this topic mention that the thread on the inserts in the frame are Metric. Which I can accept considering how the imperial bolts were damaged when i tried fitting them. Will have a chat with SNG barratt.
Cheers