The gist of the attached letter is that the Brits and Americans were working together on Anti-Tank grenades in 1940. In fact the fuze in the M9A1 (as against the M9) owes its design to the No 68 Grenade fuze.
The Brits purchased a million 'Trombone' M9A1 grenades in 1941 but didn't like the fuze (despite the fact that it was of British origin) and redesigned it, and the shaped charge, to produce the No 85 Grenade but too late for the war.
The Brits purchased a million 'Trombone' M9A1 grenades in 1941 but didn't like the fuze (despite the fact that it was of British origin) and redesigned it, and the shaped charge, to produce the No 85 Grenade but too late for the war.