If you are not sure about the black light test check US Militaria Forum>Discussion>Shoulder Sleeve Insignia & patches>proper black light techique. Also check the ASMIC magazines for articles about this. You can do a google search, read all the info and end up with a headache! British Commonwealth, France, many other nations in Western Europe & a few others world wide.
The item "1st Special Service Force USA Canada WW2 snowy back US Army" is in sale since Sunday, June 17, 2018. This item is in the category "Collectibles\Militaria\WW II (1939-45)\Original Period Items\United States\Patches". The seller is "diablovalleyantiqueprints" and is located in Concord, California. This item can be shipped worldwide.