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Can you attach some photos showing both sides of the gun?
That is a Henri Pieper side-lever shotgun made in Belgium toward the end of the 1800s. That gun should have damscus barrels on it. During that time the U.S. was flooded with inexpensive European made shotgun, many of which were sold in hardware store and stores such as Sears, Roebuck.
The early Pieper shotguns are not listed in the Blue Book, but are typically sold in the $600 to $800 and up to $1,000 range.
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