I'm with Beags on this.
Berets are for rolling up and inserting under an airman's epaulet, thus making a target for dress regulation bollockings. And Rockapes.
Chip / Forage are pasty shaped for a reason.
The only exception is a battered droopy SD on top of the head of a kipper fleet pilot, which presumably was stored on the hat and coat stand behind the seat.
I have a 14a too. Helped me to pretend when I was in the back of a Herc. I had nothing to put in the pockets.