I almost always let a dealer know if I see a 
mistake in a cel ID. At least the first time. If 
I write to them again about later misidentified 
cels depends on how the given dealer responded to 
the first time I wrote.

Anyhow, most dealers seem to ignore messages of 
that nature. But not all ignore it! Some are 
grateful to have mistakes in the description 
pointed out before someone buys the cel and then 
complains the information was incorrect. So I 
would say, write to the dealer and let them know.

But before writing, make sure *you* know your 
stuff inside and out. For example, if you're 
writing to tell them a cel isn't an OP, first 
make sure you've seen *EVERY* different opening 
for the given series. For longer series, this can 
be as many as five or more different OPs. Also be 
sure you've seen the *original* OPs. Domestic 
releases are almost all edited in some way and 
pieces of the opening may have been cut. (I'm 
told this happened with Lost Universe.)

Many Sharp Smiles,
--Drac (cleaning house. . . bah. . . ~_~)