They came out great!  I don't have any examples 
(not that I'd post them anyway--other peoples' 
cels are other peoples' cels whether the 
lines/one of the layers/etc have been added by me 
or not)  You should be able to do it yourself if 
you have a steady enough hand.  I suggest getting 
extra-thin tranparencies for the best color 
preservation of the layer(s) beneath.