I don't know how to tell you this.  I've checked 
over and over, and I'm like 98% sure... that this 
cel you've got here... is an opening cel!  yay!  
I watched this part of the opening again and 
agian, pausing and going frame by frame, and it's 
still a little hard to tell, but it sure seems 
like it's from the OP.  So, gratz!