New York, Westchester, and Boston cars in California during WWII

In a 1948 issues of Trains Magazine I found a photo of New York, Westchester, and Boston MU cars in Santa Fe Springs, CA. What’s the story behind the cars and how did they end up in California? The article says the cars belonged to the U.S. Maritime Commission. I know most of the cars ended up in Boston commuter service.

I looked on the New Haven Railroad HTA website and they had an article in their magazine about these cars but the back issue is no longer available.

You are correct about most being in Boston commuter service, where they replaced the last of the New Haven’s wood open platform cars. They were replaced in turn by downgraded parlor cars reseated with commuter seating when the postwar parlor cars begain arriving in 1949.