This seems like low hanging fruit. This stamp is a Type II. And, it's not Orange Brown. So..., it's an 11A. So far so good.
It shows a center line to the right. (stamps are left pane) The center line is doubled in the lower third. Great clue!
Only two plates are reported to have double center lines. Plate 2, early and late states, and plate 5 early and late states. Early states are eliminated in this case due to "not Orange Brown" 11A.
So we are left with 2L late and 5L late.
Plate 5 is stated to have the frame line doubled, the entire length of the plate.
Plate 2 late, is listed showing the center lines as, "the right center line much heavier than the left". More telling, "opposite the first and tenth rows, the line is single"!
So this pair has to be, 9L & 10L of plate 2Late.
My problem is the lack of guide dots that should appear on top row stamps...???


Is it possible, that's a misplaced guide dot above the left diamond block of the right stamp?
