Hi Mike,
I wish I had the time and money to retro fit mine, but not now. Beside mine runs sweet, just the controls are old and a pain in the a$$.
As far as the bearing, if yours are good, I'm not sure I would change them either. They were built like tanks and mine is an 86 that runs smooth as silk. I had a former Hardinge tech come to my shop to assist me with recommissioning my machine just after I got it and he said just that. The machines were sturdy as rocks, but the controls are just old.
Anyway, I'll keep an eye on your project.
Just Mike
Two Haas VF-2's, Haas HA5C, Haas HRT-9, Hardinge CHNC 1, Bother HS-300 Wire EDM, BobCAD V23, BobCAD V28