2 3/8" X 3 1/2" (58mm X 86mm)

No markings

Picture courtesy Bill Ostrander

2 1/4" X 3 1/8" (55mm X 78mm)

(front crown inkstamp)

Т-ва М.С.К.

{Matthew Sidorovich Kuznetsov}

Picture courtesy George Sukhoff

2 1/4" X 3 1/8" (55mm X 78mm)

(ear ink stamp)

Picture courtesy Bob Berry

2 1/4" X 3 1/8" (55mm X 78mm)

(ear incuse)

Picture courtesy Bob Berry