Oh, man , this is some great stuff. Chandu was a radio serial (created here at KHJ in 1931) (and film series) about a crime-fighting mystic. Looks like someone was part of the fan club or something. Imagine getting a letter with Chandu as the return address.
Chandu’s Book of Magic is actually a 1932 promotional piece from the Rio Grande Oil Company “to advertise their new Rio Grande Cracked Gasoline.”
Photo by Americana.