Dunbar Popcorn Special Horse Wagon 
In Dunbar Records Called 
"Old Style (O.S.) 750"
1906 Dunbar Catalog

Please note Happy Hooligan in Popper Window.  It is not mounted on the Steam Engine.

Dunbar Popcorn Wagon Model 750
1907, 1911, 1913, 1915, 1920, 1922,
1926, and 1929 Dunbar Catalogs