Bonnet lifting

[Twistygit]

Advice needed for new owner. Noticed the bonnet lifting more than normal, on checking the forum there were a number of posts saying that this could be down to the fibreglass breaking around the bolts, hey presto there is the answer. My question is what are the best materials for the repair job? Also I intend to renew the hinges whilst the bonnet is off are the Steve Heath hinges the best one to use?