Hello,

Here is some information about the french expert Calves (he is indeed one of the most well-known here in France). His fees are 2 % of the catalog value (Yvert et Tellier) if the stamp is genuine. If the stamp is false, the expertize is free of charge.

From now on, he delivers a certificate free of charge for all stamps he expertises (it's very helpful when the stamp is false and you want to be refunded !)

Here is a link for his website : http://www.timbres-experts.com

Have a nice sunday !