If they don't want it, the National Naval Aviation Museum in Pensacola probably would.

Thanks all for all help. Between here and the WMF I learned a lot about these Good Luck Flags. I’m going to hang onto it for a while.

This must be an older image of "Cobra King". The original Cobra King from WW2 and the relief of Bastogne is now housed at the National Museum of the United States Army.   Leigh  

I have wondered about the same thing about a WW1 SSI on a uniform tied to the 20th.   I currently have a uniform in my collection named and ID'd to a 2LT in D Company, 335th Quartermaster Battalion, sometimes known as a Labor Battalion. This unit was one of the many auxiliary units attached to the 20th Engineers, perhaps as a part of the Forestry unit. It would no doubt be interesting if they wore the 20th patch, or maybe nothing at all as you've speculated. I'm further along in solving the mystery but nowhere near done.  

I found that this style started in 1944 but I have no idea how long they continued to be used 

That is some thorough research! Well done N. Jerry  

Sending it off to the world war 2 aviation museum in Colorado. Seems like a good home 

As much as I do love a good German helmet- yep not US or any bring back info. so locking this one down~!

I have this DCU cover.  It has no suits and a different stamp in side that I am not accustomed to seeing on this type of cover.  Is it real?

Trying to figure out the era of these collar devices. I am leaning towards pre WW1 but how far back I am unsure.  Thanks for any assistance  the only marking is “bronze” on the infantry pin