I received the cel stapled to the background, so 
it's not as if I picked up a background that was 
similar to the production scene and stapled the 
cel to it.

Since it is easy to staple a cel and a background 
together into a package, there is little reason 
to believe that that alone justifies the 
background as a matching, production one. We 
don't see it too much, I think, because it takes 
a little more effort to staple things together 
(although not a lot, but if you add it up over 
hundreds of cels...) and both the cel and the 
background are ruined forever by staple holes. It 
is easier, and no damage is done, when you slap 
(not literally, of course ^_^) a cel with a 
background together without attaching them in any 
way.

---Trebuchet