Tom, good questions, but I dunno the answers. Am wondering if Teflon would be a better choice?
Ah yes, those AF Gondolas are a bit light-footed, ain't they? Load 'em up with scrap! Of course they won't roll as easily now, so your trains will have to be shorter! Oh wait, that wasn't the original plan, was it?
Think I'll go back to rebuilding this Model A carburetor for a friend, later!