That’s really nice!  I would say you are correct in believing it is a sweetheart pin- a gold chain would connect to the other missing part.  The missing part may be an officer’s rank insignia.   Based on the direction the eagle’s head is pointing, it is post 1941 manufacture.   Can you post another photo with a coin next to it to provide size context? 

A better pic 

Hi all, I collect vintage Tiffany items and came to acquire this badge, which from my limited research seems to point to a navy officer beret badge? It is sterling and 14k gold. I am curious what that ring at the bottom might be used for. To attach a chain to keep the brooch safe? Will this be a sweetheart pin?  It weighs 7g in total.  thanks for any insight!   

I agree 100% with everything you say, and it also doesn't help that this was a "universal" camouflage that was worn everywhere in the world.  In other words, there's nothing special about them like there is with desert camo or jungle fatigues.  A set without provenance could have been worn in theater or worn by someone who washed out of basic training.

During World War Two it appeared as though militaries largely emulated the design of British uniforms all green or similar.    After some point militaries began emulating the style worn by U.S. military personnel which is camoflogue. 

Doh!   I leared something new! Thank you.   hyrax222

If that insignia was Chinese-made (as I think one should be), I’d expect the yellow and blue sections to be silk rather than felt.   I don’t care for it.  

A "cracker jack" impression would be interesting. Burning the waste is extremely important to maintain hygiene, but this is seldomly portrayed... I can't imagine why... ;)

It's a British L3A1 Bayonet see below.   Best,   V/r Lance    

At Ford's Custom Guns in Florida, it appears that stripping the plating and then bluing the parts could run up to $1000.00, with a turn-around time of 9 months, but don't quote me on that, you can go to their website and ask.