No one has said sign in question is a Fake, but the seller's attitude has raised a red flag.
You would think he would want his bidders to be informed before bidding ?
I don't see a 100% return policy mentioned.

Reproduction/Fantasy Cans
http://i124.photobucket.com/albums/p2/oldegaspump/AllCansMASTERTHUMBNAIL_zps4bfdbbc7.jpg
Rnd Can Re-lids