Since Trump stooped the war on coal an F-4 could be a fun toy. Fuel is cheap and abundant.
Stripped of weapons and defensive systems, that probably drops an hour or so here and there.
/s
I was in college in the latter part of the 1970s. The school got a secondary computer for the students, a Harris 24bit unix machine that was originally designed for aircraft carrier use to aid reducing the turnaround time in aircraft maintenance.