Mystery Diner

A reader sends in the following information and pictures on a (partial) railroad car used as restaurant in Washington state:

This railcar diner in Oakville, WA appears to be a wood-steel car similar to those at the Chinese restaurant in Seattle.  It is cut off at the building, so is only half or 1/3 of of an original car.  The restaurant, "Jag's" is for sale.  I am not sure of the future of this car. The windows are starting to fail, however many good stained glass panels are there for what is left.  It's probably a good parts source, or a display of some sort for a museum.  The steel parts appear to be in decent shape.  I hope this diner survives, or that a museum gets it for some good purpose.  Maybe you guys can figure out more of its history.

(Photos by the pseudonymous "Jim Portman")

I'd agree that it appears to be a wooden car later steel-sheathed (like that narrows it down!)  Other than that I have no idea.