WW2 British manufacture US stamped Thompson 50 round magazine pouch which is basically a reverse Lend Lease item. The majority of the pouches used by the British for Thompson Magazines both stick and drum were US manufactured and purchased early on by the British Purchasing Commission and paid for by cash then supplied under the Lend Lease Act. Later in the War as the German threat was no longer an issue in England and the British could ramp up war material production and I guess had extra time and material and made both Drum and Stick Magazine Pouches and supplied them to the US. I would think the upcoming D-Day Invasion of France had production running at full speed to supply all the soldiers of various countries getting ready.
This pouch is in perfect un-issued condition and has the shoulder strap, the front flap is U.S. stamped and inside the front flap is by the manufacturer – A.C. and date stamped 1943 with the word British Made. Made in the British Canvas which is slightly different than the US canvas.