Just a quick update, I hope to post some pictures later. Just because of the size, the number of pieces we have, and the time the electrolysis would take, we opted to try other methods first.
After doing some preliminary scraping and knocking off a few chunks of the initial rust, we put the pans in the oven and set it to self clean. It helped a little, but probably wasn't worth the time and energy. Dawn and baking powder make a pretty good cleaning combination. Soaking in white vinegar and water also helped to a certain degree. The Navel Jelly really cut through the rust, but left a residue that was hard to take off. We repeated those steps in various orders and the pieces were better, but we couldn't get them looking the way we wanted.
At that point I was ready to head to Menards and begin the science experiment. However, my wife did some digging on the internet and saw a video demonstration on YouTube for some stuff called Evapo-Rust. It is the absolutely great. I wish we had found it a week earlier. It is a liquid and is about $15 online for a gallon. You can get it at Ace Hardware but it was a few bucks more. It's nontoxic, can be reused, and does a much nicer job than the Navel Jelly. All you need to do is submerge the pan for a relatively short period of time (from just a few minutes to overnight). Rinse and a little light scrubbing; the results are amazing.
It is almost like Christmas. The rust was so bad we could not make out too many markings. As we started cleaning the brand names begin to appear. It has been an education looking some of them up to see where and when they were made. I don't know a lot about the history of cast iron, I have always just had pans that I enjoyed cooking with. Now my curiosity is peaked.
We did get some bees wax pellets to mix with flax seed oil to season the pans with. Hope to start doing some of that this weekend.