As far as I know, sketches like gengas or 
something were not released.  I only say this 
because I've only seen cels from this game--and 
even that is a rare thing to find.  As for the 
background, Cindy can confirm this for you, but 
I believe her BG is a color copy...but who knows 
if the BGs for this game were really "original" 
anyway since cels were made only to become 
digitized.  The BG images could have even been 
made on a computer....not a clue for sure 
though.  lol  But anyway, you must throw a party 
every day since you now have a small, tangible 
piece of this game forever.... treasure it, lest 
you make the rest of us angry.  hahaha  ^_~

Take care!
Rekka