TOPIC:

I am working right now on separating the mufflers after removing the whole setup from the bike. They are stuck pretty good... Rusted outside, I am sure 20 years or so of sitting got mufflers a bit rusty inside.

I've been searching the internet but there is nothing about removing rust from inside the mufflers. Then the next step would be how to protect them. They would stored and would not go on the bike anytime soon.

The standard mufflers have been manufactured cheap. The chrome plating is thin and the steel used not very high grade. Trying to remove rust would involve degreasing, soaking in citric acid and rinsing the mufflers many times. Due to the internal construction, the baffles would restrict the movement of the rust sludge, getting them completely clean is not feasible. Stopping the rusting with some media resistant to the high temperatures inside the mufflers can be difficult.
The original mufflers are "consumables" and most chroming companies will not touch old ones since they ruin their expensive baths due to the soot, rust and grease inside.
Ari makes replicas from stainless steel, the inner tube construction is improved preventing the heat expansion ripping effect of the originals. Stainless steel can be polished again and again´, damaged chrome not.

Finally I managed to disconnect the mufflers. Lots of digging out the old seals, soaking, and actually not that much pounding. Now I have a good look inside
It doesn't look bad! I also got to get the pipes shiny, except spots which are rusty.
The pipes look solid. Very happy. What I am going to do is stick a sand blasting nozzle inside from both ends and give it a shot. Then some I will seal one end off and fill it with vinegar, just like people do with fuel tanks. Then I am going to spray heat resistant exhaust paint, and eventually spray with ACF-50 anti-corrosion aircraft compound.The rusty areas on the outside I will spray with a galvanizing spray paint until one day I will re-chrome them.