I tried to find the fairly recent thread on radiator cap restoration, but couldn't

. Someone suggested using Windex and quad-ought steel wool. Worked wonders!

I spent the last two evenings using plenty of elbow grease as it is pretty slow going. My Windex had a little vinegar (acid) in it which I think helps. Last photo compares my restored original to a reproduction. It is not a bad repop, but there are differences in the brass rivet and some details in the letters.
<font color="blue">
Big thanks to the fella who suggested the Windex and 0000 steel wool</font>

!