Weak semi-circular mark in bottom left corner

a

Mark above slot

Mark in bottom left corner

a

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

No mark in top left corner

Double-mark in top left corner

a

No mark near center on bottom ridge

Double mark left of center of bottom ridge

a

Line at 10-o'clock of stud 4

No mark between stud 2 and 6

No mark between stud 2 and 6

No mark between studs 2, 3, 6 and 7

No mark near left corner on top ridge