[F4U-1_Corsair]

try making a new folder in the mods folder, and take the modname\3do\plane folder from the details mod, and the modname\3do\cockpit folder from the cockpit mod? don't blame me if it doesn't work, but thats what seems most likely without being able to see the mods myself. the end result should be modname\3do\cockpits (from details mod) and plane (from cockpit mod) so that both cockpit and plane folders are in the 3do folder.