Hello folks,
I've got recently a replacement Nasville T-o-m from American master luthier Roman Rist. The thing is great; have a look.

http://www.youtube.com/watch?v=me5StBLu_h4Roman's description:
"I manufacture a Direct replacement bridge for your Nashville tunamatic
No pot metal, no more corrosion, no more collapsing in the center, no more rotting out your saddles.
This bridge is CNC machined from a solid block of aircraft quality Stainless steel to exacting tolerances.
Through tests on different Les Pauls, I have found increases in sustain up to 3 seconds!
The bridge locks into place with allen screws once the action is set and never changes.
The best part is that the bridge installs with NO alterations to your guitar, it screws right into your existing inserts"
It's NOT cheap but if you want the best give Roman a shout at
www.ristguitars.com