I've been watching for them too and they do NOT 
pop up often, unfortunately. Hobby Shop K used to 
have one other one that was posted with the one 
that is still on the site, but that sold long 
ago. (IMHO, it was the better of the two.)

I am extremely fortunate to have one nice cel of 
Count D - he's even got the little bat-winged 
thing on his shoulder!! - on it's way to me as we 
type. ^_^  I can't wait to get it!! (Thankyou to 
wndrkn for pointing me to it! ^_^)

But those three are the only ones I've seen so 
far. My real wish cel from that anime would be a 
nice cel of Medusa - specifically one that shows 
her outfit (any one of them) - but I have yet to 
see a single cel of any of the "pets". Do you 
have a scene/costume that you have in mind for 
the cel of Count D that you're looking for? As 
long as I'm looking for myself, I can keep my 
eyes open for you too. ^_^

Many Sharp Smiles,
--Drac (who was floored by the PSOH anime!! WOW!)