The front page of the report Roy Johnson submits to DCS Cockburn states that it was commissioned by "the Right Honorable Home Secretary". This is the US spelling; the British form would be "Right Honourable" or more usually "Rt Hon". Also "Rt Hon" applies to individuals not the offices they hold, so the correct form would have been "The Rt Hon [name of individual], Secretary of State for the Home Department".
When Felix discovers the gun Nicky has been caching for his political group, he says, "I haven't seen one of these since Italy in '43." However, the gun is a Beretta M12, which began development in 1959.