It has applied gold letters "US" to the front of the wing. The wing also has what I believe is the early Whitehead & Hoag (THE W H) hallmark incised on the reverse.
Please let me know if you have a different opinion on this hallmark. The wing is about 3 1/8 inches long and is as good an example of this wing as I've ever seen. An outstanding piece of history seldom available on the open mark containing such a rare hallmark. The wing has a nice aged tone to it and it has not been polished or cleaned. The item "Pre WWII US Army Air Corps AAC Balloon Pilot Wing Whitehead & Hoag" is in sale since Tuesday, April 30, 2019. This item is in the category "Collectibles\Militaria\WW II (1939-45)\Original Period Items\United States\Pins". The seller is "lbiman" and is located in Trenton, New Jersey. This item can be shipped worldwide.