of these at one time, and they were all discolored only on one side. Some more so than others, but always only on one side. I wished I could find the one I have with one inlay gone. If I ever do I'll scan it and post it, but it doesn't have a perfectly shape weight. I think that is why I had my theory about the way they were made. Your idea of them laying on one side to cool makes good sense, though.
I really appreciate your patience with me. I really want to know more about all this, eventhough I am an "old timer" at it, there is always more information to be learned. One can never know all of it, nor too much.