New (to me) english tin pans, best way to clean

[das fisch]

I was able to get a set of old english tin pans today; 2x4 drop flue sap pan and ~2x4 divided finish pan, they are in overall really good shape. being old they need a good cleaning and a few pin holes patched. I have a buddy who is a copper smith and has done repairs on similar pans in the past, so that's not a big deal.
But my main question is, what is the best method to get these things 1) ready for solder and 2) then ready to boil.

Here are a few pics of the pans.

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Thanks in advance!

[Rossell's Sugar Camp]

I have never worked with english tin before so take my words with a grain of salt. but anyway I have worked with mild steel. With my old mild steel pans I scrubbed off the loose rust and then cleaned them with baking soda and then rinsed it really good with water. This got rid of the rust flavor.