Julian,
I like your setup and had seen it posted elsewhere on the forum. I would like to emulate it but I can't as I have too much "stuff" in the rear that gets in the way, not to mention that I have a center console shift which would add some rose joints that are akin to bind. I need a passenger seat for the wife and whomever wants a ride. If I didn't have to have the seat the bind issues would be minimal. I may not give up on the idea of a rod shift just yet. Keep it in the back of the "Things to do" folder. Your setup is straight forward and simple, but is best left to the right hand drive cars.
DRB cars have the combination of rod and cable from the center console, which might be a good choice except for the same problems.
Bill