What is the value of a Iver Johnson knox-all 12 ga bouble barrell shot gun?

The value of an Iver Johnson Knox-All 12 gauge double barrel shotgun can vary significantly based on its condition, age, and any unique features it may have. Typically, prices can range from $200 to $600, with well-preserved or rare models fetching higher amounts. For an accurate appraisal, it's recommended to consult a firearms expert or check recent sales of similar models.