Identifying 1c Franklin Stamp

Hello
During the isolation due to Covid,I try to identify the few USA stamps.
Being a beginner in the United States stamps with the help of Scott specialised and "stampsmarter" I try to identify them alone (colors confuse me)
I started with the middle stamp:
-perforation 11x11
-flat printing (off set on back)
-dimensions 19.2 x 21.5 mm
-color green?? deep/dark green ?
I think it is Scott#552.
My question concerns the left edge of the stamp (white part larger than 2 mm) where the "Guide line" should appear and the hight of stamp 21.5mm
Any indication is welcome. Thank you.

You are going down the right path. I agree, the center stamp is a 552. If this stamp were from a pane of 100, then yes, it is wide enough at the left side that the guide line for cutting should be visible. It isn't, so you have something else.

Thus what you have is a 552 booklet stamp, cut into panes which are 2 stamps wide and 3 stamps high. The full press sheet being 10 booklet panes wide (and and 6 panes high) with one vertical and one horizontal guide line means that most of the booklet panes will not have a line to show. Also the cutting on the panes is somewhat erratic as evidenced by the wider margin on your stamp.

Thank you John Becker
I had not yet studied the chapter "Booklets, panes & covers" in the Scott specialised catalog. I found something new: the types of sheets for booklets.
The top and bottom stamps are Scott 632 (19.25 x 22.5 mm Perf 11 x 10.5 green / yelow green)