heee, sorry I'm so cranky, its just been a long 
few days and ALOT of questions. :)

basically a cleanup drawing, or genga, etc...

is a drawing that looks EXACTLY like the cel. 
its a cleaned-up drawing, just what it sounds 
like. :) its the final drawing that the cel artist 
basically traces to make the cel.

personally I think having the cleanup drawing, 
which is often slightly more detailed than the 
final cel, improves the value of a cel.

hope that helps explain! and I hope I didn't 
insult anyone, I really wasnt trying to. :)