It seems to be a Belgian IMO too.

You can find lots of information about Belgian guns on those sites.

http://pagesperso-orange.fr/mallorquina/source/page0index.htm

There you can possibly retrieve the manufacrurer, the controller or the age of a Belgian made gun from the marks.

http://www.littlegun.be/arme%20belge/a%20a%20site%20belge%20fr.htm

There, you can find many informations about manufacturers. There were plenty of them.

If you send good pictures of the gun to the little gun team, and allow them to publish them, they can help you identifying your gun.

Anyway, if it is a Belgian Gun, it has been made after 1830.

Va t'in tch�re !