Didn't post earlier for 2 reasons.
Firstly the recommended man in TR circles is Stuart, but he's in Grampound road near Truro which isn't very close to you.
Secondly he is a now a TR restoration specialist although he has worked on other classics in his earlier days.
However the reason that I thought of suggesting him is because he is particularly expert at panel repairs and especially using lead. He presents lead loading/bodywork seminars at the TR International weekends and is extremely well respected.
Just thought that there may be something that he could do with the wing that you have.
He is
http://watermillcarriage.webs.com/(No relation, haven't used him myself, but I've bought a panel from him and seen his work on other people's cars)