stikpusher
Also, USN yellow wings aircraft did not have bare metal surfaces. They were painted in either aluminum lacquer, or light gray paint, depending upon type...
Was it type, or was it time period? I thought the light gray was replaced by the aluminum lacquer in the late 30s. For example, the F11C had light gray on its metal surfaces (forward fuselage, landing gear struts and wheel pants) and aluminum dope on its fabric surfaces, except for the upper wing surface, and the tail. The light grey on the metal was replaced with aluminum lacquer for the last configuration of the colorful markings, before the overall light grey was implemented.