3" X 3 1/4" (74mm X 80mm)

 (dome inkstamp)

                              N-80

{Zapel Electrical Porcelain}

Picture courtesy Bob Berry

3" X 3 1/4" (74mm X 80mm)

(dome inkstamp)

(Skirt Incuse) K / 941

{Chodziez Porcelain}

Picture courtesy Bob Berry

3" X 3 1/4" (74mm X 80mm)

 (dome incuse)

{Jedlina Zdrój porcelain}

Picture courtesy Bob Scafe

3 1/8" X 3 1/4" (77mm X 80mm)

 (dome inkstamp)

{Chodziez Porcelain}

Picture courtesy Bob Berry