Backroading around SW New Hampshire - the West Coast of the state in more ways than one - I stopped for lunch at the Mt. Pisgah Diner. Hamburger with mushrooms and bacon, glass of juice, cup of coffee, out for under $7, including tip. The menu stated that the structure is a "Worcester Diner" from the 1930's. I have been to a lot of NH's diners, but I had never noticed such a reference before.
The Worcester Lunch Car Company, now defunct, built about 600 railroad-car shaped diners in the 30's and 40's, scattered all over the country, but mostly in New England. Those who are up on diner history apparently regard these as important historic items.
Images and more info.