Salaams Archer ~ Looks like you have nailed it as the swan not only that but a superb list of stamps to boot ! To me ... I'm no specialist in Moroccan weapons... the quality looks over and above what I normally see from there.. to that end it could be a French maker (Franco Jewish?)(Jewish Moroccan) either in Morocco or outside... I dont know. The work looks excellent and once again with the stamps/hallmarks nice work by you in presentation.
Regards,
Ibrahiim al Balooshi.