The brand of unknown master Riga is the initials of the IMS, the first floor. 19 in.

IЗМClaymo Master Manila Ivan Zinuev - Initiators of IZM

АНЗClaymo of unknown master Riga, initials of ANZ, 1848.

Я.МClaymo Master Miskov Yakov Fedorović - Moscow - initials of Y.M. - 1880-1900.

И-АClaymo Master of Alexeiev Ivan Alexeiwich - Moscow - initials of I-A

IСДKleimo, unknown master of Moscow, initials of ISD 1744-1753.

МНThe Klemo Master of the Novovilov Mihail Efims, with the red initials of the "M" - the end of 19 - the beginning of the 20th century.