cdnum,
You are correct that you see "wiping" on your stamp. Wiping marks are common on many stamps including flat plate #552.
There are many characteristics of your stamp that indicate that it as a flat plate printing. Rotary stamps have much more detail which is most obvious in these areas:

I agree with Clark(cfrphoto) that yours is a common #552. I also agree with Clark that you should look at images of rotary press perf 10 Scott #581 to get a good idea of what "tall" rotary printings look like. The simplest definition of #596 is that it has the appearance of #581 but has the perforations of flat plate stamps such as #552.
Your stamp does have the perforations that are characteristic of #596, but is a flat plate printing instead of a rotary printing.
It is definitely a #552. These things are not easy to notice without help. Hopefully this reply will help you to see the differences.
Many cancels are the same on common AND rare stamps.
Initials on the back of a stamp DO NOT necessarily mean anything important.
The most important thing is if your stamp is flat plate or a rotary printing. It is definitely a flat plate printing so it can only be a #552.
These things absolutely can be confusing. Hopefully Clark and I have explained it so that you fully understand.