Vince: I believe you are thinking of C-54 . A C-53 looked like a Gooney bird but it was just a troop carrier , had a small door similar to an DC-3. There were so many versions of that aircraft it would make a book full. Talked to a old Douglas engineer one time at Long Beach ,said that they really didn`t know too much about the new metals, so they made every thing extra heavy.
Well it stood the test of time! Cargomaster,Liftmaster,some where is the C-74? May be we will get it figured out some time?
Sure am having fun ! big max 1935