The beginning credits to the show gives the date as [Saturday] the 22nd March; thirty seconds later the official at Beirut International Airport stamps the date on Volnay's passport as [Tuesday] the 13th May 1969.
Alex, attending Sir Curtis Seretse's hair, is merely using his scissors to make snipping movements well away from his client's head, and no cut hair can be seen on his barber gown.
One of the Mark Caine novels on the bookshop carousel appears to have no title on the front cover, and none have them on their spines. There are also two different copies of "Identity, Mark Caine!", a blue one with the comma and a purple one without.
Another of the books Stewart flicks through is a copy of Walter Tevis's "The Man Who Fell to Earth" with the author's name covered by a large photo of Jason King. The rest of the cover design matches Gold Medal's design for Tevis' story.
Michele's surname is 'Duplay' in the credits, but Annabelle writes it down as 'Duplac' - which is also how it's pronounced in dialogue. Similarly it is Talka in dialogue but Takla in the end credits.