Got this today with other American patches. Sorry if it's  foreign. Next to Vietnam era SF patch. Thank you.

Now that is interesting. It seems it would have be cheaper to use an observer wing.

A number of years ago, I found this "blank" LGB wing, showing how the base wing was made for the addition of the various ratings.

Nobody does US Navy khakis.   They do US Army Khakis.    Some Navy guys wore army khakis.

Hi Folks:  Just picked up  "Davis" pistol belt size "Medium" at a Vietnam veteran's estate sale.  A "different" buckle design than the "standard".

Hi Folks:  Recently picked up this 1961 Camillus utility knife at a Vietnam veteran's estate sale.  

Not sure if this helps but I paid $20 for one about 3 years ago. Very similar to yours although I believe it is a 1943 example. Couldn’t say what they’re going for now though.

Boots have the “Plumber’s crack” on the back.  These boots were never worn…and the veteran was in the Quartermaster field (Supply Guy)

Wikipedia has a bunch of pages of various sized units  - https://en.wikipedia.org/wiki/Division_insignia_of_the_United_States_Army, https://en.wikipedia.org/wiki/Brigade_insignia_of_the_United_States_Army etc etc. links are at the bottom with the other sized organizations. Or you can go to the Institute of Heraldry web site https://tioh.army.mil/Catalog/HeraldryList.aspx?CategoryId=22&grp=2&menu=Uniformed Services If you happen to find the patch for the 3rd Mongolian Horde or the 219th Underwater Messkit Repair Company, I would pay good money for those :)