The stigma of the test master of Leningrad - Mitin Alexander Nikolaevich - initials "AM" - 1842-1877.

Mitin Alexander Nikolaevich, the stigma of the test master is divided into two parts, in the upper part of the stigma the initials "A" and "M" are depicted, there is a point between the letters, the line passes in the middle, in the lower part of the stigma, the year "1861" is indicated.(1842-1877) Form: rectangle