SP 4107 is one of 124 rebuilt C-40-4 steel bay window cabooses of which there were 200 cars originally built in 1961 by Pacific Car & Foundry. The C-40-4 rebuilds were performed in 1974 and 1975. The car resides at the Western Pacific Railroad Museum in Portola, CA but is eventually being moved to Stockton, CA as part of a trade for CCT 24. The first image was taken on April 24, 2005 and the second on July 15, 2004.