I ran across this website via the Park Trains group and found it interesting. It is a group devoted to collecting and restoring Divco milk trucks, those little snub-nosed units we remember (with the ever-squeaky brakes) when milk was delivered door-to-door. Divco was in business from the 1920s to 1986, so produced many more models than the ones we remember from the 1950s.

http://www.divco.org/index.html

Incidently, the site does have a page devoted to minature park trains, for the required rail content, found here:

http://www.divco.org/trains.htm