Unknown "USN" Insignia ID: Officers' Steward Combination Cap Insignia

[Basic Rifleman]

What are they, and who used them? I'm guessing by the construction and makers Amico mark they're WWII era. Any help would be most appreciated. 

[P-40Warhawk]

Officer's stewards wore these on the combination cap. 

[Basic Rifleman]

Awesome. Thanks so much! Marked as solved.

[Salvage Sailor]

For illustration...

 

Harold Ward, Pearl Harbor & Guadalcanal Veteran

USS SAN FRANCISCO (CA-38)

[Salvage Sailor]

and another, Pinoy this time

[Salvage Sailor]

...and a USCG veteran First class

[manayunkman]

Some great pictures.