HISSIN I had the mod done by Mal Wood and he does use the existing shifter.
I also had the box rebuilt and got a clutch and remote bleed valve from him. He did good work and no surprises. I have used a gear stick from a BF Falcon(probably the only Ford bit on the car). So all good.
I know a couple of guys have done the mode themselves I guess my "boys" just are not big enough to do it myself