Where can you look up serial numbers on a Iver Johnson shotgun?

To look up serial numbers on an Iver Johnson shotgun, you can start by checking the underside of the barrel or on the frame, as these are common locations for serial numbers. Additionally, you may refer to the manufacturer's website or contact collectors' forums and organizations that specialize in firearms for further assistance. Historical references or guides on Iver Johnson Firearms can also provide insights into serial number ranges and dating.