Templar says he "knows an excellent quote about star-crossed lovers". He is referring to William Shakespeare's "Romeo and Juliet": "From ancient grudge break to new mutiny, / Where civil blood makes civil hands unclean. / From forth the fatal loins of these two foes / A pair of star-cross'd lovers take their life".
Although he is credited for the story, very little of Leslie Charteris' original concept actually made it to the screen. He later adapted his version of the story for his book "The Saint Goes West", which included several digs at the Hollywood movie industry.
The Latin and chemical name for a "Mickey Finn" is given in this script as "fulminor curare," obviously an invention for humorous effect. Translated to English, fulminor curare approximates "(to) ensure lightning." The usual compound, but in high-strength doses, used as a knock-out drug was chloral hydrate, ordinarily a sedative. The term is derived from Michael "Mickey" Finn, an early 19th century salon manager who doped drinks to relieve patrons of their cash.
The British Guyana stamps are among the first ever made. The 1 cent Guyanas are usually blue, but there was one sheet printed in yellow by mistake. The sole surviving stamp from that sheet is the most valuable stamp in the world. The stamps shown in the film are 1c cent Guyanas worth a lot of money, honey.