greetings dsb0328, and welcome to the Lefora Patrick Nagel forum!
the Nagel Commemoratives are not hand signed nor numbered by the artist. the signatures you see are signed-in-screen (sis), that is, the signature is part of the production process of the artwork just as much as any of the colors, or largely in the case of Patrick’s work, the color without color, gray. if you visit ebay, you can get a loose picture of how the for sale valuations of the commemoratives vary widely. the market is tilted towards quantity supplied (the buyer) as there were many of the NCs made, particularly as the number increases, up to 15, the number of each produced increased dramatically, thus reducing the monetary value. i have seen prices as low as $40 for an NC print. i paid even less for mine, decently matted and framed. if you are going to try to sell them framed, than realistically, you are looking at a local market; shipping frame and glass is prohibitive. your better route is craigslist. or this forum, like ebay, you may be able to move the prints alone; in which case, a shipping tube for graphic art is adviseable.
Shannon is hand signed and numbered (as i understand) by the deceased artist’s former wife. this serigraph will hold more monetary value than the NCs as, you can see, the hand signed production was limited. finding Shannon on ebay shouldn’t be a challenge.
uploading photographs to the forum is possible. the directions to do so, i do not know off hand but can be discovered with a little trial and error.