.
This is a Early AVG (American Volunteer Group) Flying Tigers Leather Blood Chit from the WWII US China Theater - worth $250-$300 for a gennie with provenance, like yours. (copies are $30)
Blood chits are usually associated with the AVG Flying Tigers, 14th Air Force Flying Tiger squadrons, and other units operating in the CBI (China/Burma/India) Theater.
They were sewn on the backs (both inside and outside) of the Army Air Force or US Navy/Marine Corps flight jacket or flying suit.
They were intended to keep a downed pilot from being killed or otherwise harmed by the local population, many of whom had never seen a Caucasian before.
The flag or flags of the government(s) of the area(s) being flown over were shown, as well as a message written in the local language(s).
Paraphrased the message is; "I am a downed American Airman. I have come to help rid your country of our common enemy, the Japanese. If you keep me safe, provide me with food, water, shelter, and medical help, you will be rewarded by my government when I am returned safely to my countrymen" (The US Allied Forces).
This is a WWII US CBI Flying Tigers AVG Group ( 1st American Volunteer Group) regimental flag for the China/Burma/India Theater - IDK a value.
Prior to US involvement in WWII against the Japanese (pre-Pearl Harbor,7 Dec 1941), US military pilots (and their support groups), anxious to fight enemies of the US, volunteered to fly/fight for the Chinese gov't at that time, to fight the Japanese - who were already aggressively active in Asian combat.
The volunteers were temporarily released from their US service obligation, so that the pols could say that the US Gov't wasn't involved in China, then (the survivors) re-patrioted into the US military after Pearl Harbor.
.