I still have a couple of those that were Xmas presents as a kid. They cover parts of China.
I never knew any history behind them and always assumed they were either for the Doolittle Raid or the Flying Tigers.
14th Air Force, most likely.
At one time in my younger days, I dated a young lady who’s Grandad gave her his Doolittle raid jacket. She showed me so that I could translate the Chinese text for her. Talk about touching a piece of history. I was in awe.