2 3/8" X 3 1/4" (58mm X 80mm)

 (dome inkstamp)

{Giesche, niemen notch}

Picture courtesy Bob Scafe

2 1/4" X 3 1/8" (55mm X 77mm)

No markings

{note niemen notch} 

Picture courtesy Bob Scafe

2 1/4" X 3 1/4" (57mm X 82mm)

(dome inkstamp)

{note niemen notch} 

Picture courtesy Bob Berry

2 1/4" X 3 1/4" (57mm X 82mm)

(front dome inkstamp)

(rear dome inkstamp)

{Cmielow, niemen notch} 

Picture courtesy Bob Berry