Regarding the name of the cat, Asmodeus. Asmodeus is a demon who specializes in spreading lust. He preys on common people and royalty and even divine beings.
Michael Byrne plays a Nazi interrogator in this film and would go on to play a very similar role, that of a vicious Nazi officer, in Indiana Jones and the Last Crusade (1989). Whereas Michael Sheard plays Adolf Hitler in both this and the aforementioned Indiana Jones film. Sheard also portrayed Hitler in Hitler's Last Secret: Seeds of Destruction (1978), The Dirty Dozen: Next Mission (1985) and Hitler of the Andes (2003).
This movie was based on the Geoffrey Household book "Rogue Male", published in 1939. The main protagonist and the main antagonist went unnamed in that novel. However, Household wrote a sequel--"Rogue Justice"--that was published in 1982. In that novel, the main characters' names were revealed: Raymond Ingelram and Von Lauen. The lawyer is named Saul Harding.