muddy22,
The word is not Lauer, instead it is Lauf, which means barrel in German. Absent ID markings, it is very difficult to find out who the actual maker is. It may not be possible to find a date of manufacture, closer than the range of dates above. If you post another photograph of the entire area of the bottom of the rifle barrel, where the 7.8/57 is located; I will give it a try.
Mike

Last edited by Der Ami; 03/15/18 09:55 AM.