I made twin sticks, i was surprised at how easy it actually was. Why you would do it? it gives you the option of 2Low, 4low, 2high, 4high and a true neutral. I think it also looks really
Anyway, to save $200 plus freight i decided to work it out myself 
If you look carefully, i drilled a hole through the ball, it's not in the right spot i drilled it a bit too low on the ball. I only found this out when i put it in and i couldn't get 4low. I then took the 7mm pin out and it found all the gear very easily.
Take one standard sierra transfer lever, and cut it down the slotted section, i used a 1mm cutting disk, it probably won't work if you use a 3mm as it would take to much meat away from the stick.
To replace what i cut out i used a piece of 0.9gal plate i had around, it was way to thin and i probably took out more like 1.5mm as there is vibration in the disk and no one is that accurate to keep it straight up and down.
At this point you need to slide the spring and attachment cup onto the sticks. Do this now as later it won't be possibly.
so that's the bottom end done, i grabbed another stick, cut the ball off and split it down the middle till i found the weld joint that it comes factory with. the cut one side off.
So once you have it in the lever hole in the Tcase, work out how much you will need to bend the stick to get them to clear each other, then, the bits that touch the shifting rods need to be bent out the right amount to fit nice and firmly, and not sloppy.
I forgot to take photo's of this next section but, i had to cut the stick i had just played with into a wedge shape, along the still round side. This is because it had to clear the other stick, i had to do it to both piece's. Here is it in and functioning
I still need to use this Tcase, so not sure what it will be like in the real world, and im going to by some industrial strength rubber gloves cut some holes and hose clamp it to the sticks, not sure what ill do about the boot in the car...
Hope this helps
