small update in the wait for a solution to above problem:
WRX sti 6mt kartboy shortshifter install
So i bought a second hand sti shifter, no bushings and the following install actualy took me near a week because i thought i was cool and could skip the under the car steps. My pain your gain. This subject is not new territory but i thought id reiterate a few points i got stuck on. The install is not complicated and i recommend it as sti sts seem to be more common second hand compared to liberties.
1. Jack up your car and keep it up!! ( i ended up doing it 3 or 4 times in lack of foresight)
2. remove your current gear stick assembly + plus cigarette lighter. (12mm spanner/shifter x2, straight q tip pliers, hammer, tiny screwdriver or allen key to remove lock pin)
3. remove bushings from old shifter and place in new shifter and insert new shifter into position (hammer, flat head screwdriver, CAREFUL!!)
4. You NEED to go under the car for this bit. On the passenger side of the gear box near halfway down the car remove the heat shield and fit the biggest allen key you can into the reverse lockout cam.

5.Next step is making a spacer to fit, i used a bit of scrap aluminium tube i had and filed it down to fit. Fitting means that spacer allows lock pin hole on the cable to line up with bottom of gearstick slot (i used an allen key to measure things up)

6. cable tie the excess cable (shifter is 1inch shorter) underneath the car with some JDM goodness so that it does not rub on the prop shaft.

7. More jdm goodness to hold pieces in place. Holes on the boot are different between liberty and wrx but no biggy.

8. Replace lock pins and trims etc in cabin and THEN remove allen key and replace heat shield underneath.
I found that perhaps the plastic holding the boot up may need a trim to drop it down because there is not much finger space between the collar.
Rough approximation of throw of new kartboy 6mt shifter:
