Time to break out some test gear.
The best tool in my box is a 12V test lamp. It was an inspection lamp for the cigar lighter but I cut off the plug and bared the wires and pulled them apart. I now have about 5m of wire on each side of the 12V lamp (not LED, a real 12V bulb).
If you hook one end to the battery negative you can go hunting for voltage with the other end.
Start with the coil positive. It is fed with a red with tracer wire. Take it off and see if you have a Dim bulb in Run and a bright one in Start. I suspect you will have nothing in Run and it is because the red with tracer wire has a break somewhere between the coil and the ignition switch, possibly at the resistor wire. This is why when you jump from the battery to the coil you are bypassing that break and it runs great.
Now look at the light blue wire on the S tab on the solenoid. It will be live in Start only. Look at the red with tracer wire on the I tab. It is being energised in Start and that is then being carried up to the coil. As soon as you let go of the key that voltage is not being fed to the I tab and the engine dies.
Now using that tool you can look for voltage all the way back to the switch which you can assess at the column connector. The fuse box / ignition switch diagram has it on the extreme left, the red with tracer wire to "Ignition and Alternator".
BagusJeep lives in Bali.
1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE