I've read alot on the internet about restoring old hand tools and steel/iron parts using a home brewed electrolysis process. (WoodNet member, rarebear, has some excellent resources on the subject. Here's another link, too.) I've become interested in pre-WWII hand planes as well, so these two interests naturally converge.

I started my own experiments with electrolysis with a plane I picked up for $1 at a yard sale. As you can see in Fig. 1 and 2, it was covered in rust.

First, I found a battery charger at a flea market for $10, but managed to pick it up for $6 due to its 3rd grounding prong on the outlet plug being broken off. However, it does work. I started with a 5-gallon bucket I had on hand, a 1x2" piece of wood and some extra electrical wire stripped and separated down to the black and white wires.

I connected the red charger clip to the white wire and, in turn, the other end of the white wire to the scrap iron (aka 'sacrificial anode', Fig. 5). Next, I connected the black charger clip to the black wire and that to the plane body (to run plane parts separately, Fig. 6).

At first, it didn't seem to do anything. I saw a few bubbles on both metal objects, but I figured that was simply trapped from lowering them into the water. So, I unplugged the charger, added several teaspoons of baking soda and plugged it back in. In a few minutes, it was off to the races. Bubbles swarmed off of the plane body. Eureka! (See Fig. 6)

After several hours, the water is cloudy with foul, red gunk. (Fig. 8) You'll need to change the water and baking soda a time or two.