If you have the ability, you can make what you need.
I made mine. I started with one of those old-time U-shaped spinner "ratchets" with the knurled spinner handle. I cut the spinner part off to use as my shift knob. Then I took 2 7/16 nuts that I threaded onto a 7/16 bolt, put them close together and welded them together. Then removed 7/16 bolt, put my spinny knob on top and welded that on. Smoothed the nuts, painted them black, and voila, I have a redneck shift knob!
If you have a specific knob you'd like to use that is a different thread, you could remove your shift lever, cut off the incorrect threads, get a bolt of correct thread and appropriate length, remove the bolt head and weld it to the shift lever.
Or, do like I did, put 2 nuts on a 7/16 bolt so you can weld them together, weld a bolt on top that has correct threads, and you'll have your own adapter.
Just tossing some ideas out there to spark your thot process!