hummm..you know you could be right..I have a cel 
b/g  like that..also one where they just taped 
more old junkie acetate to the bottom of 
it..just for the reg holes.
   Im thinking along the same lines as you, 
Drac.. that they are just being cheap..trying to 
cut down production costs..
  I wish that I could spend just one day 
watching them do a sequence..just to see how its 
done..I wouldn't even pester em for 
freebies..hehehe. but to watch the application 
of the machinery and how the camera moves around 
a set up..that could explain some of the mystery 
marks ona few of my cels.

  (I could see me gettin thrown out for poking a 
key animator  and asking him "OI---you done with 
that yet? Can I have it?")