T5 Offset Lever Shift Rail Diameter?

I'm trying to build a mockup shifter using parts from a T5 / T56 transmission in which the offset lever which the shifter ball joint connects to is from a T5 (highlighted above). I originally used a wooden dowel to press fit into and after measuring the diameter, it's like a weird off-dimension of like 14.5mm. Unfortunately, linear rods only come in either 14 or 15mm. Right now, I have a 14mm metal rod, but there's a bit of significant play/wobble when I insert the rod into the bore hole highlighted.

I'm wondering if anyone here knows what the true diameter of the stock shift rail is and whether my offset lever part is just defective or something...

It seems like you can also get the shift rail separately, but does anyone know where to get the linear bearings / bushings for it so that it slides smoothly?

Thanks in advance.