Awh, Dude, you missed an awesome Zartan cel, if you go to http://www.vegalleries.com/gijoe/ there's an index files of all the cels they had, and man were there some awesome ones. I checked their Transformers page today and almost all of the decent cels without the stupid human characters are all gone.

There's another animation art gallery, Art Toons that has a ton of GI Joe cels, I don't remember if they have any of Zartan, I think they have some of the Dreadnoks though.
I think their url is http://members.aol.com//arttoonsart