2 3/4" X 3 3/4" (67mm X 92mm)

No markings

Picture courtesy Bob Berry

2 3/4" X 3 3/4" (67mm X 92mm)

No markings 

Picture courtesy Bob Berry

2 3/4" X 3 3/4" (67mm X 92mm)

No markings 

Picture courtesy Bob Berry

2 3/4" X 3 3/4" (66mm X 96mm)

No markings 

Picture courtesy Dave Dangora