I'm seeing that U.S. Army OR's didn't have a forage cap after 1942. The hat is Army. Might be an officer's hat somebody stuck an OR's badge on.
I think the cap badge may be Viet Nam era.
Rummage around here. Caps, Service, Wool, Serge, Olive-Drab (Specifications QMC 8-5D Caps, Service, Wool, Serge, Olive-Drab, Aviation Cadet (Specification QMC 8-5E Dated 12 December 1934).