I seem to remember watching AA opposing PA's changing ends in the 60's, with half of the cars facing one way and half facing the other, no turning of the trains or engines. I was also told by friends operating the 3751, that the wye at the Marine base is too tight for big steam (shaves off flange), which is why they have to wye 3751 out at Miramar.

Whatever they did in the steam era, I don't think ATSF was turning trains or engines on wyes or turntables by the late 60's. I also took Amtrak in the early days and seem to recall that they had the coaches set up half facing back half facing forward, and just changed the engines, until the arrival of the Amfleet cars, with push pull cab cars around 76-77.