I mentioned earlier that I was using a Shift Knob extension. Normally, I'd probably have gone through TWM, but after reading some of the modern horror stories about delayed shipment/poor communication, I decided to find another route. Ended up locating this on Amazon:
https://www.amazon.com/Nissan-Manual...knob+extension
For $13 it was pretty hard to pass up as a test item. Attached a pic of my shift knob + extension installed. It's not very pretty, but for now it does the trick. My plan at the moment is to have my brother make a custom extension, matched to the diameter of the shift knob itself, with 2 small set screws on about halfway up the barrel to hold the shift boot.
Shift knob is about 1 lb. Between that and the TWM short shifter setup I've got, it rows through the gears like butter.