Well how detailed do you want me to be on this build?
Disclaimer... I am a carpenter by trade, I also have a very large back ground in metal working/machining, all disciplines of welding including some certifications. I am not a stove restoration expert by any means. I will make mistakes, and some of the information that I post will be incorrect. I'm human.
I did a whole bunch of research on the different acids available for treating rusty cast iron.
Turns out Muriatic acid is the gift that keeps on giving. Once applied to CI it gets into the pores and continues to react with the base material unless completely neutralized. I'm not looking forward to destroying a 100 year old stove just to save myself some work.
Phosphoric acid on the other hand when applied to rusty CI turns the iron oxide into ferric phosphate. Ferric Phosphate has a black appearance and mild corrosion resistance. Plus it looks very nice when done. Most drywall screws are sold as phosphate coated so you get an idea of what the interior finishes will look like once treated.
Because a lot of the stove is interior passages and non serviceable, I'd prefer not to paint them. Stove polish is only going to be applied to the exterior of the stove so a corrosion resistant coating on the rest will be beneficial.
I also decided that Electrolysis is how major rust removal will be accomplished. I only have minimal parts that need rust to be removed with this method. The rear CI 90 on the back of the stove is pretty bad looking but still structurally sound.
If this is more than you'd like to know tell me. I can tone it down a bit and just post pictures.
Thing is, that while I complete projects like this you guys will appreciate it, plus if start going the wrong direction steer me strait.
My wife just says "that's nice honey"