Will someone give me the definitive word on if those spots of rust can be removed from wheels and regulators, etc. without leaving evidence that it was done...

Dennis,

Since regulators and regulator springs are flat mirror polished steel parts, they can be resurfaced then refinished and the same can be said for any other flat steel part including screw heads. Winding and ratchet wheels are usually decorated and unless one has a method for recreating these types of patterns, you're kind of stuck with at least some evidence. There are many people here who also collect firearms so maybe some of them could chime in with recommendations for products and processes for improving rusted steel.

William

Thanks William....I've heard that grinding/polishing off the rust leaves pits behind that look just as bad..

For surface rust on firearms, the "old school" method is 0000 steel wool and sulphur-based cutting oil, such as is used for thread cutting on iron pipe. That will remove surface rust without destroying color case hardening and/or blueing, because both those finishes are actually a form of controlled surface rusting to begin with.

On highly polished and engine turned watch parts, it will not work. The only other rust removal method I know of for watch or other polished parts is refinishing as mentioned before, or removing the rust by electrolysis. But electrolytic rust removal converts the red rusty color to a dull grey. (One of them is ferrous oxide and one is ferric oxide, but I can never remember which is which - I took Chemistry 101 too many years ago). Anyway, hope this helps some.

I've used this product.
EVAPO-RUST
http://www.evapo-rust.com/

Won't damage the part and complete removes the rust.
The bad side effect, if you leave the part in too long, is the surface turns dull gray. :-(
So, re-polishing will then be required.
You need to time the submersion in the fluid to minimize the dulling effect (while getting all the rust removed.)

The Good part, its non-acidic and enviro-friendly (rise with water).