Ham and Egger's dimensions are of the image size the have nothing to do with the perforation rate.
It hard to tell from your image, but I suspect you have found dry-print dues from the very late 1950s, which would not have any paper shrinkage during the printing process - and thus be larger. I hesitate to say what exact Scott sub-number because Scott has changed the numbering of these at least once or twice in the last decade (and several years of the Specialized have errors in the due listings, which they have been notified about).
Here is an image I made several years ago showing compound perforation dues (J80+), It does not show the colors as well as I had hoped, but:
dull carmine of 1931 to about 1943
scarlet from about 1943 to 1958, a war-time change
the dry-print scarlet of c1958-59.
The three printings can be identified by eye (so put the ruler away). The ink of the dry print is slightly bubbly like a thermograph print, especially in the ovals at the bottom - in addition to the whiter paper.