It looks like your not taking the fanart down that is your right. But I'm sure you wouldn't want someone to take your cel and create a fanart from it not to mention put it up for sale. Whether you made it now or before bad timing .This cel this fanart portrays a cel that just won 1st place in the female contest of the anime beta awards 2009.. I have had someone take my cel image and create mni-cels and sell them on ebay. I'm no longer part of this community but had to just add my 2 cents into to this . Good luck with whatever you decide to do .
I have to side with Nathalie here as I doubt she used the award winners cel to make this. Like she said this is an iconic scene in the series and she may have started it before the image was even made public and coincidentally finished after the image was shown. Also there's some differences between the cel in question and her fanart. If I was the owner of the cel, I'd definitely buy this as it compliments the actual cel perfectly(the moon in the bg is a nice touch). From what I can tell she's not the type to make duplicates of her work just for profit.
