Dave: I'm sure others will be along shortly, but the markings and that horn triggerguard seem to say is that the gun's probably of German (Suhl) manufacture and bbls are Swedish (Svenskt) steel. That "Sandvik" is a little confusing; unless I'm mistaken that's a town in Norway (maybe location of a retailer??).

Are there any other markings on the gun? Any proof marks on the barrels or frame? If so and you can post photos or describe them, we could probably come up with more info. Good luck, Jerry