It was easy to prime and paint the interior while building. Did the nose and main sections separately before they were joined. And BEFORE the side skins were put on. Then painted the inside of the side skins before riveting them on. Rattle can, looks great, holds up just fine.
NOT a lot of trouble to do, scuff with scotchbrite pad, wipe off with acetone, spray the self etching primer. Then the paint per directions.