Hi,

I've actually seen all but the Don Quixote wolf 
that you mentioned (not sure where that's from).  
Again, I think they were mostly at Ebay (you 
should try a search for 'rare cels' ... that's 
where you'll usually pick up more of the older 
stuff) or you might also try Van Eaton 
Galleries.  They have a broad range of cels from 
some Anime to American.  (I just got a Supergirl 
cel from the newer Batman and Superman series).  
But in the past they've had everything from Jem 
to D&D, to GI Joe.  Good luck in your search