Classical Numismatic Group recently auctioned a mysterious silver drachm as lot 114 in their recent auction at the New York International. The catalog notes the drachm is struck from the same die as Rosen 311, which is made of electrum, and Dewing 1008 (silver).
Perhaps one day sufficient specimens will exist to do a die study. I wonder if the electrum coins were struck earlier, later, or at the same time as the silver coins.
Unfortunately I didn't have a chance to inspect the coin myself. The auction photo is clear. The style of the reverse on the electrum specimen in Nancy Waggoner's catalog of the Rosen collection shows a square with a rough pattern. That reverse looks nothing like the four-part reverse on the silver specimens.
It would be unfortunate if the Rosen coin is false, as I believe an electrum gorgon/incuse to be.
I had a great time last week at the New York International. I was glad to see familiar faces. Hope everyone is having a good 2014. Feel free to reply in the comments section on this coin or any other topic related to the show or the new year.