Help With Identifying 2c Washington - Flat Or Rotary

Finally reaching the end of going through all of Washington/Franklin stamps I had. Came across this specimen and I'm having trouble with calling it either flat or rotary. It is definitely perf 11 on both horizontal and vertical. I cannot find a watermark on it. It appears to be Type I. There is some coloration on the back that would indicate flat plate printing. This would make it a 499. But when overlaying a known flat plate on the front, the margins aren't lining up very well and resembles a rotary version. Is it possible to have this type of variation on a flat plate version?

Since there is a straight edge on one side, could this perhaps be a booklet stamp? As I recall, the booklet designs were slightly different from their pane counterparts.
Added: To clarify, might your stamp be a single from a booklet pane 499e as opposed to a 499 from a pane of 100?

I agree with JLLebert - booklet stamp. Booklet stamps of the 3rd bureau issue era are shorter and wider than their sheet stamp counterparts.

Ok, that makes since. Its a single from a booklet (499e). Thank you.

I never knew that. I still learn something every day.

Jack Kelley

One final clarification. The differences in the design size for the 499 booklet vs. pane stamps is due to the direction of the paper grain. I recall reading somewhere that shrinkage on flat plate stamps was about 4 times larger across the grain as opposed to with the grain. Booklet stamps were printed on paper with horizontal grain whereas the pane stamps were printed on paper with vertical grain. This explains why a booklet 499 is shorter & wider than its pane counterpart.
Note that though a 499 booklet stamp does not have a separate catalogue designation, the same is no longer true for the 1928 panes that were printed on special booklet paper. Scott added these to the U.S. Specialized Catalogue a few years ago.