Recoil Rob,
I never heard of such a gun, but if I were trying to track it down, I would look for an Ernst Kerner gun built on a Meffert Dural frame. He is known to have built Vierlings on Meffert Dural frames. He was a son in law of The Mefferts and son of well-known Emil Kerner, consequently had access to Dural frames as well as the technical curiosity to work out the problems with the hammers/triggers/selectors. Also, his drillings/vierlings were often built on Blitz system, so were not limited to two hammers. Thanks for the info.
Mike
