The artifacts of the stamp are that you can delete it within Adobe Acrobat Pro, however it regenerates on a mouse-move because the stream object keeps it persistent.
If you try to edit the pdf source - which is tricky, there's a chance that the file will be corrupted.
If the stamp is a stream, we can interrupt it by disconnecting the computer from the Net, which I did.
Then using the Adobe Acrobat Pro, I selected one of my annotations, right-clicked to get the popup, and selected "Show Comments List".
Select the nefarious watermark/stamp from the List, right-click to get the popup and select "Delete". Do this on every page where the affixation occurs.
Save the File under another name. My application crashed, but not before saving the file!
Open the new & much smaller file; note that all the watermarks/stamps are gonzo.
In my case, the file size of my 3-page document shrank from 300 kb down to an impressive 60 kb. All the original data and annotations remained intact - sans the watermarks.
~Good hunting :o)