yitbos
Weapons both functional and defective are traded all the time, and clandestine "adjustments" are often made according to the fluidity of the situation, and generally follow the national interests of the nations involved.
35 year old personal grudges, if existent, simply do not play into national interests. If so, somebody in Washington must really hate the Brits for hanging Patriots, because we sold the Argentines complete submarines armed with really neat stuff, and on credit, no less.
Additionally, (be prepared to laugh) the Brits must have been feeling guilty about Israel, because they sabotaged Saddam Hussein's Babylon gun by not delivering the breech section (and two others), after building them and getting paid for it.