Good info guys.
I don't believe the cranking of motor with a slightly slow speed starter or weak battery would produce enough oil pressure to reach rocker area. We will be inspecting that. Next test is oiled cylinders.

Will take off covers and spin push rods by hand, check rockers, springs, and watch overall operation and oil flow during crank speed.

The hand crank pointer/rotor test will be repeated. We will reverse direction, as suggested, to observe slop.

It would be nice if we detect faster speed crank after oiling cylinders by hand. It would be nice to see at least 4 cylinders go to 100+ psi.

Next opportunity for OP is Mon-Tues

I have just asked him if he ever changed oil. If he has a cartridge oil filter or spin on. If he changed cartridge.

EDIT: Oil not change for a long long time. Filter not changed. Unknown if that's 33 years or not. A sitting motor will form condensation during weather cycles and have dripping water inside valve covers and crankcase. This can turn into a living environment for "swamp thing". May not pump thru unchanged filter and into motor....or may pump some sort of unknown chemically altered fluid into motor and "stick" it up and dry it up. In addition, may have allowed washing during the test drives. A series of eventual loss of compression.
I want to hand flush all of the valve train and let it drain into pan, then drain pan. Change filter, add 5 qts thin oil by pouring over valve train and do the oil squirt compression test. What should top of motor be hand flushed with? Gas, Mystery oil, kerosene...... keeping in mind is will be drained out. Don't want it to circulate anyway.
Don't want to add more bad 33 year old oil to the situation. Just trying to give the oil-in-cylinder compression test the best chance, as this may be the last chance, before teardown.
My fantasy is we get enough compression to start, oil circulates and fees up motor, then change oil a few times and "whalla", it's fixed. aye? No damage. I am hanging on to that it has spark, is timed and getting gas.

One of us is gummed up and washed out........me or the motor.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn