that would be me sir.

I thought about doing a how to thread. To remove the knob, carefully pry up on the leather base, there are like 6 retainers. Then lift up the leather boot, you can then see how the knob is attached to the shift rod. Push down on the knob and turn it, there is a roll pin that is holding the ears of the shift knob on, it is spring loaded, nothing major, just don't lose the spring. pull the knob and boot off. You will see an O ring in the groove of the rod. That rod is 9/16". So I ordered a cue ball (but the guy will do any pool ball) from a guy named Pete in Lilburn Georgia on ebay. I asked him what thread he would cut for 9/16", he said 18. So then purchase a cutting die (not rethreading) I got mine on amazon, and because of the size I needed a tap handle also, inexpensive as well. Back to the Jeep... unbolt the shift rod from the lower shifter, two bolts. Take to the bench vise, remove the roll pin, cut off the top at that O ring groove. Smooth out the cut making just a very slight chamfer all the way around. This will aid with getting that die on nice and straight. Soak the die with light oil, then carefully and squarely start threading the die, more oil! Constantly back off slightly, to clear the chips, use more oil and keep cutting. Compare the depth of the cue ball to know how far to run down your thread.
Still with me? The next thing is separate your boot from the shifter knob. It is just a tight fit around the base. Searching through storage bins I came up with a rubber shock tower bushing. I made up a jig using a bolt, washers and nut, to hold the bushing then inserted the jig in a drill press and cut a groove in the side of the spinning bushing using various sharp objects. This groove is used to hold the top of the leather bag when installed. The bushing fits tight over the rod and the boot neck fits tight over the bushing. Two months and no issues. Pete sends teflon tape with your shift ball order. This will actually help snug up the threads to eliminate spinning while shifting.
Now if you want to do a custom shift rod, which would be really cool, put up pics! As for my recommended seller on ebay, there are others out there. This guy was fast and responsive, and the product was top quality. My apologies if I detailed the die cutting process too much. $19 for the shift knob, and less than $25 for the die and handle.