I know the work of Robert L. Hamon. Does the sig look like that? I have over a hundred of his marbles, but none that look like that one. He has two nephews who did made similar marbles. That one looks blue and yellow in a clear base? Correct one I'm looking at? They are big football fans in West Virginia and they call their marbles in that color and design, "Mountaineers". One is John Hamon Miller and the other is Boyd Alan Miller. John mostly signs "JHM" and Boyd signed "BAM". There are several signatures of Robert L. as they changed over the years. Somes "Robert L. Hamon", sometimes "R. Hamon", sometimes just "Hamon".
the marble in my avatar is a Robert L. Hamon.