The complicated record changer Stephen and Mary are listening to is a Capehart 400 series. These cost between $1,000 and $1,700 at the time ($17,000 to $29,000 in 2017) depending on the model and cabinet - and that does not include installation.
In the scene in the hotel room between [Virginia Bruce] and [Herbert Marshall], she sings a bit of [Cole Porter]'s "I've Got You Under My Skin"--a song she had introduced in the musical 为舞而生 (1936) two years earlier.
When Mrs. Holland goes to the bar and orders a "hooker" of rye, she means a larger-than-normal amount--basically a large gulp--of undiluted rye whiskey. The word "hooker" in this context was a slang term used from the 1920s through the 1940s.