I bought this record 135 sash clamp which had a good coat of surface rust.
It was put in my electrolysis tank for a few hours which removed the rust.
It was then polished up with a scotch pad & WD40.
I repainted the blue bits as the electrolysis had loosened the paint in places.
Finally it got a coat of liberon lubricating wax to protect the bare metal.
Looks nice, seems a shame to use it!

A green scotch pad & wd40 removes it & gets you back to a dull grey, perfect for painting, more rubbing gets it shiny. A wire cup brush on a grinder or drill gets a shiny finish but tends to remove metal and paint doesn't stick too well to the polished metal.