>so buildings in SF and Oakland could have been torn down and replaced in the meanwhile

1) by 1970, I had already been working for the RR for about a year.

2) yes, they could have been torn down, but urban ruin-all didn't get started until several years later. Besides there would have been signs of a complex this big in Oak and/or SF, and there were none on any of the industrial tracks in SF at the time I was working there.

The old GE place in Oakland near 14th St and Wood St was very much like this place, only a lot smaller and more cramped. I went in there with a switch engine a few times, and it reminded me of things I'd seen in the rust belt on the east coast. SF is especially doubtful because it is on the end of a peninsula, and to bring this type of heavy hardware in for distribution across the Bay's bridges would be uneconomical (especially before the bridges were built).