John Gilbert initially was cast as Carlos Margoli. Promised to be his comeback role after a string of flops, he filmed a few Technicolor costume tests with Marlene Dietrich (whom he was dating at the time). He had a heart attack in his dressing room only days before shooting started and immediately was replaced by John Halliday. A few days after his abrupt replacement, Gilbert died of alcohol-induced heart failure. Peggy Stallings' "Flesh and Fantasy" states that Gilbert and Dietrich were living together when she tried to use her influence to have him cast opposite her in the film. She withdrew her support when the actor renewed his friendship with former fiancée Greta Garbo. After this, Dietrich renewed her relationship with Gary Cooper, who got the part. Gilbert's fatal heart attack occurred on the same day Cooper's casting was officially announced by Paramount.
The car Tom is driving as the "Bronson 8" is a 1935 Pontiac Improved Eight convertible coupe. Madeline is driving a 1935 Auburn 851 SC Speedster. Only about 500 were made from 1935-6. In excellent condition at auction in 2025, it could fetch well over $100,000, with some examples reaching over $1M.
Gary Cooper's character mentions he makes $125 a week. which is equal to an annual salary of: $6,500. That equates to about 5 times the average annual salary or wages in the USA at that time. In 2025, that would be an equivalent, due to inflation, to around $2,900 a week or about $153,000 a year.
The price of 2,200,000 French Francs that the jeweler wants for the pearls would equal $134,500 at the time or nearly $3.2M in 2025.