Recommendations for Restoring Router

[wireties]

We bought an old router at an auction. It is a beast with a 14' by 9' bed. The motors came with the router but nothing else control-wise. All the axis move but we need to clean it up. We are refitting with a 4kw spindle, new motor drivers and LinuxCNC.

What are the best methods to remove surface rust of the gear surfaces? Anybody had some good experiences with different methods and chemicals?

We are also thinking of switching from sprockets and chain to HTD belts and pulleys in a few places. Wise move?

Any innovative efforts to create a vacuum setup?

TIA