I have a circa 1901 J P Sauer & Son / V L & D Knock-About SLNE. This is 7 !/2 lb gun with 30" tight choked barrels. It does have 70 stamped into the extractor face. The stock at the comb was hollowed out with a leather covered cork insert installed. With this comb insert I tend to think it may have been intended for the traps, otherwise would have presumed a waterfowl gun.
Miller/TN

Miller/TN
I Didn't Say Everything I Said, Yogi Berra