From Dan Smith's slide-sharing collection, Andy Carlson sent me slides of PGE and ONT box cars in southern California circa 1958. The PGE box car was newly built in 1958 but the ONT box car was built in 1947.
The PGE owned fewer than 100 box cars in 1955, and only about 300 in 1959 (after buying 200 new cars in 1958). So I imagine sightings of them would be very rare indeed in the STMFC era. I believe there was a large aluminum smelting operation in British Columbia, in addition to lots of lumber.
You must remember that until about 1957 the PGE was an isolated railway connected to Vancouver, BC by car barge. At that time I would think that it would be very unlikely for a PGE car to stray very far from home. After the track was laid to connect the PGE to North Vancouver and new equipment was purchased, the equipment would start to roam further afield. This ties in nicely with a spotting of a New PGE box car in California in 1958.
