I have been into antique tools for a long time, and belong to a tool collector organization, even though my interest is in usable hand tools. The tools with real value are pristine factory new and/or rare. Many old axes are common and inexpensive. The rusted tools have relatively low value. However, for example a stamped or embossed axe is a sought after collector item. Most collectors I know hate vinegar or other acid baths. They hate shined up to "better" than new. They prefer aged patina. Electrolysis or wire wheel (on axes only, not on a scratchable tool) are the processes I see most collectors use.