I detailed in my restothread how i redid them. The whole way, including new rubbers.
Like others mentioned, they are clear zinc electroplated.
You can seperate them if needed.
Im not sure i would again seperate a functional set, its a lotta work.
They do run immensely better now.
I would also not sand blast them. It sticks inside and never run smooth again. They are originally made from folded steel plate that looks like it was slightly sanded. They have lines along the length. If you want to freshen them up take a bit of steel wool to mimic.
The etching step prior to the zinc plating will take of quite some rust and grime where you can't reach. The cleaner you bring them in, the brighter they come out.
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