Interurban Video released a film to VHS version of it years ago. I have a copy so when I get the chance, I'll see if there's a production date on it somewhere.
The minature train is indeed the "Oakland Acorn" that used to run at Peralta Park. The locomotive is a Pacific. Ken Shattock posted some photos of it on Trainorders. Here's a link the the thread: [
www.trainorders.com] (Unlss you're a TO's member, you can only see the photos as thumbnails.)
Here's a link to the "Whiskey River Railway" in Marshall, WI, where it still operates: [
home.centurytel.net]
Here's how the locomotive looks today: [
home.centurytel.net]
The scenes of the PA with the kids and the engineer were filmed at SP's East Oakland yard (which looked a lot different than it does today).