Do you have an original bonnet or has it been replaced at some time in the past?
I never really realised until i read the thread below on the MGExp forum that you can tell if you have an original or replacement bonnet.

When the car bodies were received at Abingdon final assembly line from the factory that built the bodies the first thing they did was to remove the bonnet. Prior to this 2 pilot or witness holes were drilled to ensure they were replaced with the correct alignment at the end of the assembly line.
So if your bonnet / hinge has these holes they are original if they line up they are most likely a matching original pair. If there are no witness holes on the bonnet then it is probably a replacement.
If you are sure you have an original bonnet and it’s not fitting well then may be check these holes are in alignment but beware it may still be an original bonnet but off a different car?
Read the thread at …… https://www.mgexp.com/forum/mgb-and-gt-forum.1/see-what-some-po-did-i-like-it.4149251/