Don't know where you've been, but most of those 
shows attract fangirls like flies to shit...the 
only "little known" one on there is not little 
known as much as not very popular (there's a 
difference ^^). Aaaanywhoo, moving on...as Yann 
said, he has some Now and Then cels...I haven't 
really seen very many others, save YJ. 

For Crest of the Stars, Kodomo no Omocha, Gundam 
X, and Vampire Princess Miyu, check www.cels.org; 
most of the delaers on their carry at least one 
cel from these series, as they are pretty popular.

Argent Soma...good luck. There was just a thread 
on this, actually. Basically, fangirls are out 
for these cels...as evilminion put it, when one 
pops up on YJ, it's a "fangirl monkey pile" ^^

Yami no Matsuei, as was stated earlier, is CG. 
Gomen!

Hope this helps! And welcome to this addictive 
hobby ^^

Ja!

-Misha