Ray Stanley is the fellow that Achipmunk referred to and the person you asked about (Sorry about not being explicit when I replied to your post). He is a master panel-beater. He is the fellow with the metal helmet on, Metal Man.

Do an Internet search on Ray Stanley Wheelwright Restorations and you will read many positive experiences and positive recommendations.

He does not have an on-line store but he sometimes sells parts on eBay. He does not usually make one-off parts. Many of his parts are sold by Jim Carter (in particular, 47-55 panel-body parts not made by anyone else).