I don't know about a Key System connection to the Santa Fe, but the SP interchange was as stated earlier in this thread - the small Santa Fe yard in Emeryville. When I worked an Oakland Local off the extra board we would sometimes see an Espee switcher tied up in our yard to go to beans on San Pablo Ave. Our piggyback ramp was also located there and the 4th Oakland local would bring the pigs down from Richmond, on duty there at 12:30PM. The other Oakland Locals in the 60's were the 5th Local, on duty at 7:30 PM and the 6th Local at midnite (or thereabouts, don't remember the exact time) The 4th local, on its return to Richmond Yard would double its entire train over to a departure track for the hot OAF, on duty at 12:30AM, which would immediately depart.

As for the small yard near Jack London Square, that was Alice Street yard. It had a one stall engine house where GE 44 tonner 462 was kept. They occasionally called a three man crew off the extra board to taxi down, fire up the 462, pull and load the barge then spot the loads at one or two remaining customers there. Although I was never called, it was a great day's two or three hours work in daylight for a full days pay. Although the Espee main line was literally a few feet away from the Santa Fe there was no physical connection, at least when I worked there. Sometime in the late 60s/early 70s a condo development was built on that site. The 462 was hand painted blue and yellow in the engine shed at Alice Street, I believe maybe the last one on the Santa Fe in black and silver.