2¢ Carmine 3-L-7-4
The aspect that Marler likely noted is the guide dot in the upper left corner.
Research notes:
Based on Marler's notes, Marler is suggesting that the defective transfer could be characteristic of both 3-L-1-1 and 4-L-1-1.
However, when we look at the straight edge at the bottom, clearly the stamp position must be from either position 4 or 5 of the booklet pane.
Leopold Beaudet has identified the plate position using the plate proofs at LAC.
Leo's Notes
Based on the guide dot in the upper left corner, the stamp is 3-L-7-4.
The guide dot is a "pane delineation" guide dot. There are five such
dots on the plate:
1. Left group, upright pane 7, in the margin between the stamps in rows 1 and 2 of column 1
2. Right group, inverted pane 8, in the margin between the stamps in
rows 1 and 2 of column 1
3. In the tab between booklets 3-L-2 and 3-R-1
4. In the tab between booklets 3-L-14 and 3-R-13
5. In the centre of the plate - thus, in the tab of booklet 3-L-8 or 3-R-7.