I bought this gun on an auction yesterday and i have been trying to research it, I think it is a Eibar but im not sure. The only markings on it are "made in spain" and "C.12m/m" and the marking " (JB) " and the serial number. i will Attach some pics, any help would be great. Thank You.

I am thinking the Eibar might be the proofing house. but here is a link i found that may give you some marking codes , if the barrel has any...... no way after some of the reading i have done about spains proofing methods or lack of, I would feel comfortable shooting that thing.

http://www.shotguns.se/html/spain.html

I believe that gun is by the Spanish company Jukar which makes (made?) inexpensive guns like that which were imported in the 1960's/70's. I also think Eibar is the Spanish proof house, not a manufacturer.

Be sure to check to see if there is a load in the bore by inserting the ram rod and comparing the distance it goes down the bore to the length of the barrel. The bore should be clear to within about 3/4" or the nipple.

Thanks for the replys. I was definetly not planning on shooting it at all, Just a wall hanger. Just wondering what i got when people ask.

I once had a cheap Brazilian made ~.41 caliber replica smoothbore that had a similar full stock configuration.
That small gauge gun was said to be a parrot gun for shooting smaller tropical birds and mammals in the jungle environment of South America.
They even shoot small monkeys in South America because it's difficult to preserve meat in such hot climates and a little fresh meat is better than none. 12mm equals .47 inches.
A large gun isn't really needed for small game and these small bores are economical to load. Whether it was intended for export or for use in Europe, other European countries shoot song birds for sport and as a food source including Italy. Just look at how small some of our game birds are like dove and some quail.