Clearing corrosion from the inside of the shell skin

[leftandright]

Howdy!

Taking a beat-up '71 Sovereign and turning it into a full-time residence for my wife and I. Currently battling some corrosion along the seams inside the shell skin:


Once the corrosion is cleared (I'm having considerable success based on the posts in this forum) how should I seal it before insulating? I know I would only be inviting more corrosion if I leave sections of the inside shiny.

I'm planning to seal the seams with the Tremco sealant, I'm more looking for thoughts on how to do larger sections that aren't necessarily on a seam.