A version of the mission bell marker for El Camino Real (which marks the path of the original missions) can still be seen in California today (2022).
The name of the bar seen at the end of the film, Sloppy Jose's, is a play on Sloppy Joe's bar in Key West, FL. There is a similarly named historic bar in Havana, Cuba. It is mentioned in the film "Citizen Kane."
The annual return of the swallows falls on the feast of St. Joseph, March 19th. It is celebrated in the 1940 Ink Spots song, "When the Swallows Come Back to Capistrano."
The colorful birds depicted bear very little resemblance to actual swallows.
Postwar audiences would have appreciated the allusions to the housing shortage and construction boom, as well as the cat's use of radar equipment to track the birds.