When Edward tells Freda that she should have checked up on him with "Somerset House", he is referring to the fact that it then housed the Public Records Office where one could see any deceased person's will.
Phillip refers to Broadmoor, a high security British psychiatric hospital, which has housed some rather notorious inmates over the generations.
Edward's convertible is a 1955 Sunbeam Mark III.
"I'm glad I did it, but am still wondering exactly where it got me," said Margaret Lockwood in 1973. After making the movie, she did not appear in a feature film for another 21 years.
Charlotte's automobile which Edward repairs is a 1950 Jaguar Mark V.