Navy I'm guessing

[Tim Helms]

 

[jambone]

US Marines

 

[nomad 11]

a haphazard guess. i was thinking marines also. are'nt u going to tell the story how u acquired it ?

 

[galenrog]

While it is indeed a Marine Corps emblem, it is not military issue. Obvious aftermarket.

Time for more coffee.

 

[nhbenz]

While it is indeed a Marine Corps emblem, it is not military issue. Obvious aftermarket.

Time for more coffee.

It is oddly crude, but it’s marked as being made by Hilborn & Hamburger, who did make a lot of old sterling insignia:

 

[jambone]

Looks very similar to this WWII issue cap badge. Yours probably isn't a cap badge due to the different fastener on the back, but everything else is a very close match. Nice find.