thermostat:
As for the SO vs FE question, the SO was a pilot (P3) and the FE was a mechanic (no pilot licence). Different airlines used one or the other.
I didn't know the L1011 was still being used by airlines, thought they were all gone to bed.
Whether the F/E was also a pilot was a matter of union contracts and/or airline policy. There was no such thing in a L1011 as a second officer so far as the FAA was concerned.
At TWA mechanic F/Es were hired before 1960 or so. After 1963 (the next hiring cycle) everyone was hired to be a pilot, but many had to serve their time in the F/E seat, whether 707, 727, L1011, or early 747s. None of them were called SOs. The company trained them to be F/Es.