Your oil soak is probably a better way to get screws and jammed parts freed up that are rusted together than is something like the CocaCola rust removal method.
The Cola has phosphoric acid in it and that is what does the rust removal.
All sorts of weak acid brews can be used (vinegar for one) but they do about the same as the phosphoric acid types,,but sometimes slower.
Products especially made for rust removal that you buy in DIY stores usually have phosphoric acid in them.
They are good for surface rust but it doesn't penetrate very well. It'll leave stuck screws and mechanisms still stuck usually.
Some of the rust remover products 'passify' (sp?) rust down in pitting and in close fitting parts as in this case.
Meaning the rust is left down in there,,it's just chemicaly changed to a hard, inert substance so it stops rusting.
Good for stopping rust on the old iron railing work on the porch,,but not what you want here.
Kroil works well. The ATF you are using is often recommended as a penetrating oil.
There're lots of different penetrating oils on the market, they all claim to be the best. Every one of them is if it does the job you are currently working on of course.
Warm the parts up a little and then place them back into the ATF. A little heat can expand the metal and allow the oil to get down in between the parts and threads better.
By heat, I'm only talking boiling water temp,,200F or so. Just enough to expand and contract the metal. It won't damage anything, it's way below any heat treat temps of the metal. Hot salt bluing is done at 300F for example and spring temper draw is done at around 600/650F.
It's a slow process when you have them all bundled in rust like that, but carefully working them with proper screw drivers to tweek the screw loose, or even a touch tighter to break the rust and allow the oil to seep in will also help you get there.
A few educated light taps w/a plastic or other safe head mallet will help loosen things too. Don't over do it, you're not trying to move things as so much as vibrate parts to break the rust bond and allow the oil to seep in and do it's work.
Once every thing is completely apart, you can begin a process of complete rust removal on all surfaces but you don't have to be concerned about that yet.
Holy #$%^ .....seriously volatile and highly flammable, not to mention super strong and evaporates REAL FAST leaving one heck of a smell....... I dunno.....
