I had thought on how to clean the inside of the Ranchero frame in order to prep it the rust converter, I gave it a whirl and came up with this simple contraption.
I will show you how to use a museum quality black oxide look on your bolts, and share the ingredients with you.
This is the source I used to make the rust protection solution.
https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/tannic-acid-rusted-iron-artifacts.html