From Shotgun World
You have a 12ga, 3" magnum Spanish double, imported into Germany in the 1960s by Habicht, who contracted with a Spanish shotgun maker to make s/s shotguns to be sold in Germany under the Habicht name.
The guns were of good quality, generally 12 ga, were engraved, had pistol grips and were hand checkered.
The forends were beavertail, also hand checkered
The buttstocks generally had a raised cheek piece.
The gun were sidelocks w/ double triggers.
The closest match today would be the Aya.
Look on the barrel & action flats - Spanish manufactured shotguns will have Spanish proof marks, like your gun.
