Large mark along bottom edge near left corner

Mark above slot

Mark in bottom left corner + double mark in bottom right corner (when pip is bottom right)

a

Weak mark in top left corner - no mark in top right corner

a

Double mark left of center of bottom ridge

a

Line at 10-o'clock of stud 4

Mark in bottom left corner

a

Mark in top right corner

a

Double mark in bottom right corner

a

Marks above slot on right edge

a

a

Three marks between stud 2, 3, 6 and 7

1mm recess on edges around center. No dot-pattern inside center ring. 7mm pip.

7mm pip.

a