In 2011, I bought a poster signed by the cast of Harry Potter. In 2011, I did not know so much about autograph. I bought it on the website : "Ioffer". The seller looks like serious, had good evaluations and had given me a certificate of authenticity.
Today, I looking better the poster and I feel that the signatures are false. I search on Google and fanmail. Some look real (JKR), but not others (like Emma or Rupert)
http://imageshack.us/a/img802/3808/xdr3.jpg
Can you give me your opinion? This will help me a lot
If they are fake, you know what can I do?
Thank you in advance
(sorry for my very bad english, I'm French)


