Alfred, you are exactly right on Vallejo as being the second city mentioned on the KSRO station break. The announcer could be heard in the background as the family was departing their home.

You are also correct in saying that the day train was gone by the time the movie
was made, train off date was 5-11-42. The night train lasted until 6-2-56 whereupon a new day train started up running to Eureka thrice weekly. This only lasted until 11-9-58 when passenger service below Willits ceased. After that, the Budd car made took care of what remained of NWP's passenger trade. SP finally got it's long standing wish to ditch all passenger service with the creation of Amtrak.

So, the only unanswered question is about the 2700-class engine on the speeding freight train. According to Fred Stindt's book "The Northwestern Pacific Railroad", only 2708, 2759, and 2793 were leased to NWP in 1943, which is when I believe the film was made. So, it must have been one of those.