Here below is a November 1942 Popular Mechanics magazine very short article.

The lid is a zinc canning jar lid with porcelain center on the back, typically by Ball and the type goes back to the late 1880's.

The bolt is a common vintage stove bolt.

I do know that Zinc corrosion can be removed by soaking in vinegar overnight or longer.

I haven't got these materials yet but plan to experiment after I do. Am guessing that corrosion on lid may actually help because the lid would then have different thicknesses across it when the corrosion is soaked out the lid. And a corroded lid is a cheap lid!

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