Up for sale on eBay currently, are some Nagel prints where the prints themselves seem real, but some of the signatures and numbering are not.
How can that be? Well, sometimes folks would take an unsigned print, get out their pencil, and sing it in an attempt to sell it for more money than if it was unsigned. Sometimes we've seen folks take a signed in screen print and take their pencil to it trying to pass it off as such. Every once in awhile a print that should have been signed in the screen, does not get that screen printed signature.
There are also other cases where Nagel had some artist's proof or progressive sets in his cache that he never got around to signing before he died. For example, I purchased from the estate Nagel's "Black and White Robe" unsigned artist's proof. It has the Wasserman stamp and came directly from the estate, but Pat never signed it. I know of several pieces like this, including a progressive set for "Just Looking" that is even in the book, that was found in Pat's stuff, still in the original folio Jeff Wasserman put it in for Pat. *sigh*
I will say, in thirty years of collecting, I have only seen two or three prints pop up for sale where I suspected the prints themselves were a fake. I think the fear-mongering about prevalence of fake prints has been extremely overstated. More often is is that print was real, but the signature was faked.
Back to the prints that are currently for sale on eBay, please take a look at the images below for educational purposes and come to your own conclusions. :)