Considering your use of "double", may I ask exactly what you are thinking this is or may be? Doubled die, RPM, what? I ask for a reason, so if he chooses to do so, please let the OP answer....
Thank you. Unfortunately, I see no evidence of "doubling", at least of the type you're hoping for. The photos do suggest possible die deterioration, and, perhaps, strike doubling as well. Since you're wisely researching, please allow me to suggest a couple of links that may be helpful to you... http://doubleddie.com/58222.html http://doubleddie.com/144801.html In particular, do pay attention to the differences between modern "single squeeze doubled dies" and the older more recognizable "multiple squeeze" type.
I hate to disagree, Paddy, but that's not true. It was at one time, of course, but since mintmarks are no longer hand punched into individual working dies, it is no longer the case, at least if one accepts "single squeeze" as being capable of producing genuine doubled dies. Edit: while not of the single squeeze era iirc, this still should help make the point... http://doubleddie.com/506234.html
