The lunch wagon evolved into the modern day diner as it got bigger and became stationary. At the same time some lunch wagon manufacturers, Buckley in particular it would seem, embraced then new automotive technology, modernizing lunch wagons by making them self propelled. Though the diner manufacturers seem not to have continued in earnest with this evolutionary line, self propelled lunch wagons are all over the place today, out of the backs of box trucks or built up on the frames of pickups.

Dec. 1900

1901

1903

1905

1919.
I’m not sure as to the manufacturer on this, but its lunch wagon lineage is clear. Ornate and looks very heavy.