Hello again Don,
I apologize for the confusion. I presented an argument that is incorrect. My incorrect argument was that your stamp was not a booklet stamp due to an incorrect aspect ratio. That argument would be valid for flat plate printed booklet stamps. However, yours is a "tall" rotary printing which makes my argument invalid.
It cannot be a 554c because your stamp is not a flat plate printing. It is a "tall" rotary printing.
I should have made an argument concerning the presence of perforations on it's bottom (south) edge that does not fit with your later presented booklet which you believe that the stamp came from.
From Scott Specialized Catalogue of 2006: "Rotary booklet panes issued from 1926 to May 1978 (except for Nos. 1623a and 1623c) were made from specially designed plates of 180, 320, 360, and 400 subjects."
Illustrations of each of those plates show that the bottom most right stamp would have a straight edge on the right (east) AND the bottom (south) perforations. Therefore, your stamp could not come from the position that is absent in the booklet that you later posted.
Here I have superimposed your original stamp upon your posted booklet that you believe is its source:

The aspect ratios of the outer frame lines do match. However...
The colors do not match. Regardless, that could be due to various computing related reasons.
The perforation remnants don't match.
The right hand (east) straight line edge doesn't match between them.
Conclusion: it is very unlikely that your stamp came from the booklet that you posted an image of.
I in no way intend to criticize your capabilities, regardless of age. I only wish to help others like yourself.
"I am still capable of learning."
I don't doubt that and I feel similarly in that I too have a lot to learn.
Please respond with any question that you might have. My brain is a bit scrambled at times from trying to relearn several years of calculus in a several month period. I'll try my best to provide you with accurate information. I have certainly learned a lesson to only respond when my mind is clear and when I can fully fact check my statements.
Ryan