Here is one of the suggestions from the Pre-war Pinball group. This post was from a professional restorer.
I do not like the new products, mostly because they contain modern
chemicals and some abrasives. For example, even the Novus products
have some grit, to a varying degree.
I use Johnson's Paste Wax. It contains some mild cleaners but is
mostly wax. I have never(!) found a paint or finish that it attacks,
but strongly urge you all to test your chemical of choice in a hidden
area to make sure it is not going to do bad things.
Tim Arnold, the keeper of the pinball flame in Las Vegas went to the
store about a year ago to get some more Johnson's Paste Wax and found
it missing. He checked with the management and they told him it was
being discontinued. He immediately found another source and bought up
a huge supply. I heard about it and did the same. Come to find out,
the graphics on the tin were being changed and it is still available,
and hopefully will be for some time.
I use it to wax the polished bright work on the game as well, and find
it keeps it from dulling quite so rapidly.
If you'd be interested in joining the Pre-war Pinball Group, do a member search for ohmwiz and e-mail him for information, since he started the group.
John
