The most collected series is the Safety Automatic Revolver. These are break-top (top-break) revolvers. You must identify which "Model" you have:
Based on collector Bill Goforth’s research (author of Iver Johnson Arms & Cycle Works Firearms ): Iver Johnson Revolver Serial Number Database BEST
Produced 1930s–1950s. Serial numbers often start low (1,000) and go to ~50,000 by 1940. The most collected series is the Safety Automatic Revolver
Most common for later models.
Limitations and ethical/legal considerations 000) and go to ~50