Claymo Master Erman Johann - Tallin - Initiators IOM - 1740-1754.
Similar hallmarks
ICBClaymo Master Borrowski Johan Christof-Riga - Initiators of IB
ВСClaymo Master Savel Vassili Piemenov - Costrom - Initiators of Air Force - 1849-1874
ММКClaymo of an unknown Master Pskov - initials of MK 1793.
IGDThe stigma of the master Dehio Johann Gottfried - Tallinn - initials "IGD" - 1771-1790.
Ф-МClaymo Master Maslennikov Fedor Grigoriev - Moscow - initials F-M - 1732-1745.
Moscow City Clay 1804 "Georgia Windows"