Here's a tip for folks who are thinking of purchasing animation cels…
Every so often, you see some dealer selling "color model sheet" cels from old Hanna-Barbera cartoons. Sometimes, they claim these were used in the production process. Sometimes, this is implied. Sometimes, it's even true.
But about 95% of the time when you see a hand-painted, full-color model sheet cel, what it means is this: Some person who may never have worked for Hanna-Barbera or even in the industry got hold of a Xerox copy of a black-and-white model sheet. Then they had this line art Xeroxed or otherwise copied onto a cel. Then they painted it themselves. Usually, this was all done a decade or two after the cartoon show in question ceased production.
The dealer now selling this cel may not have done this. He may have acquired the piece from someone who recently manufactured it…or from someone who acquired it from someone who recently manufactured it. But the point is that most of these pieces were not produced in or for the H-B studio. If I had a set of the right cel paints here, I could whip up one that was just as "authentic."
There's a lot of fake cartoon and comic art out there. eBay always seems to have at least one "original Charles Schulz drawing" up for bids that the Six Blind Men of Hindustan could spot as bogus. Common sense should tell you which ones would be the easiest to fake and among the easiest would be shaky sketches of Snoopy done in Flair pen, and alleged cels that anyone could have painted. They're not all fake but a lot of them are. Be wary.