Since you don't find too much info on rehabbing a RK, I thought I would document my experience. Just started tearing her down. There is very little rust anywhere on the bowl, lid, and cart. I think she will look brand new when done.
Bowl and lid - you can see bright shiny porcelain where the gunk has peeled away in a few places. The bowl actually isn't that heavy, and it is easily maneuvered with one hand.
Bowl has a fair amount of dirt/dust in it. The rust is from the charcoal grate flaking off.
Ash bowl - just dirty
Other side of ash bowl
Three DO bottom vents - they weren't rusted shut.
Charcoal grate - good shape and not warped to any extent
Stainless steel grate - this is what will take some time. There is some rust, but the grate is worth saving and has a lot of life left - these cost $200 new.
One of lid rollers. As you can see these are a little larger than those found on the smaller kettles. I noticed that this one didn't spin freely. Once I got it off, the washer and nut had melted into the body. Got my hacksaw out and got them out. Sanded the end down to get s nice flat surface -,should work fine now.
I am hoping to finish it up tomorrow with a day off from work. Got some 000 steel wool - it sounds like that works good for making these kettles shine like new again.
Mike