Early Prefab Housing in Washington State

Many of the prefab houses built by the govenment in the 1940's are still around including the one that I lived in for a year. An unassuming 400 sq. ft. 1 bedroom modern box. 1,800 were built in 1944. The City of Richland Published "home blown, the history of the homes of richland",  in 1993.  It is a great booklet. I look forward to doing some early prefab mashups for the microhousenw site.  The one bedroom prefab pictured below shows the gable roof added in the early 1950's.  
This nice web site has an overview of the Richland letter houses.
http://ebchs.org/architecture/Richland/h_letter_house.htm