I know might be a more work than it's worth type endeavor
But... wonder if you can swap out the shift fork from a T6060 to a MN6/MN12 T56.
Might be another upgrade possible to tighten up the shift rail section???
The pads look close to the same size. I dont know anyone heard of this or tried it?

 

anything is possible. If anything is off, you may as well just go custom at that point though.

for each fork / synchro, are the following the same:
pad thickness at the slider groove
L pad to R pad distance
shift interlock groove at the fork link
if yes, shift interlock groove groove to slider groove

etc.

 

Na I'm just talking easy upgradable idea's that are simple. If it tightens it up why not ! ?
It's not worth a bunch of machining a bunch custom parts for a negligable improvement.

 

Pads should be the same size. Why would you want that fork over the iron version that is easily available for the T56?

 

For the 1/2 & the 5/6 rail the intergral cast in shift links on the T6060 forks might tighten it up a bit.
I agree keep the steel 3/4.