File talk:Nicolas Dalayrac cropped.jpg

Dalayrac's picture : is François-Séraphin Delpech the real author ?

Good afternoon,
I would like to do a part of the paper about Nicolas Dalayrac in french wikipedia. I never found the evidence that François-Séraphin Delpech is the real author of this picture of Dalayrac.
We can see this picture (with more pixels) here : http://gallica.bnf.fr/ark:/12148/btv1b8416901q/f1.zoom.r=Dalayrac.langFR .
Under right arm we can read : "Rosselin, éditeur, 21 quai Voltaire."
Under left arm we can read : "Lith. de Grégoire et Denceux, à Paris."
The name of the author is never written.
I think http://www.picassomio.es/francois-seraphin-delpech-poster-artist.html is a commercial website. Is it true ?
Sincerly yours.--Fguinard (talk) 15:25, 14 August 2012 (UTC)