"British Made" U.S. Fieldgear
During WWII the United States provided Great Britain with more than 30 billion dollars of military aid. Under the Reverse Lend Lease program, the British supplied the US military with products in exchange to reduce the debt. Some of these items were uniforms and field equipment. They were usually the same design as those made by American factories, but they differed in regard to materials, since the English manufacturers used materials available in Britain. Products made through the RLL Program were incorporated into the US military supply system and were issued concurrently with the regular American made items.
What is correct? Any combination of US and "British Made" gear is authentic. Some items, like Haversacks and first aid pouches were relatively common, while others are relatively rare. It is unlikely that US troops would have completely "matching" sets of equipment- more realistic is a sprinkling of British Made items in one's kit.
Note: These items are not made in England! They are reproductions of the gear made by the British and used by American forces in WWII.