Hola Fernando,
Very nice little pistol, with its ivory grip.
The damascus decoration looks consistent with that applied by Liege gunsmiths. Look here:
http://www.vikingsword.com/vb/showth...ghlight=crolle
and here:
http://www.littlegun.be/arme%20belge...damas%20fr.htm
Concerning the loading system, i would say this is
not a muzzle loader but a 'forced bullet' example. These breeches are usually very small, specially in a gun of such short barrel, thus needing a very small amount of gunpowder and bullet size. On the other hand, it would be unreasonable to build a turn off barrel only for the cleaning of a breech you could easily reach from the muzzle of such tiny gun.
Let's hear from other members about this.