Birney Goes on Display in Bellingham

I just happened upon this article in the Cascadia Daily News, from a couple of months ago, that details the placement of Tacoma Railway & Power 324 on display in Bellingham, Washington. The car is owned - and, now, is located adjacent to - the Helen Loggie Museum of Art in Bellingham, which is a fairly new organization housed in the city's historic Washington Territorial Courthouse building. Information on this car comes from Tom and Vince Mendenhall, who restored its body on behalf of the Loggie Museum as detailed here. The car has been placed under an attractive canopy that affords an unobstructed view from the street. Car 324's status has been updated to "displayed inoperable."

P.S. Anyone know what the significance of the "704" placard on the end of the car might be? It looks a bit like a New York subway car number board, but I'm mystified as to its role on this car.