Much ordanace and weapons were made in US to UK spec. The Americans charged for ordance and fuel used by Brtish forces, but used British manufactured and supplied without paying. I have a Mossberg MB42a riflre, .22 Bolt action one of about 42,000 manufactured for UK at a cost of $10 each. They were then fitted with Paker Hale sights. Mine traces by serial number to one of the last batches of 21, 000 delivered February 1941. The top of the barrel is stamped US Goverment Property, because of course at the time the US was netural but was supplying Lease/Lend, you can't 'Lease or 'Lend' something you don't own, hence the barrel stamp. Many weapons were also supplied by voluntary donation during the 'Send a Gun to Defend a British Home campaing. Many of these subsequently ended up in Home Gaurd units. Some however, mainly Winchester and some of the Mossbergs were fitted with scopes and moderators (Silencers), these were reputed to have been issued to The Home Gaurd Auxilary Units, as assasination weapons. One of the tasks of such groups , should an invasion have happned , was to assasinate , fiendly personal who knew of thier existence!!!! and colabarators!