Look at the choke tubes.
Yes. Briley or some other company will have to do the modification.
Try www.Gunbroker.com. They are no longer produced.
300-500 USD
Browning.
Your browning auto-5 light weight was made by FN of belguim for browning in 1960.
your browning light weight 12ga was produced in 1960.
You have a 1987 Light Twelve. Value depends on condition. Expect $400 to $800 for a used gun. A professional appraisal is recommended.
k You will have to call Browning with the sn to find out.
Readily available from Browning.
The light 12 was introduced in 1947 until 1998 when the gun was discontinued as a regular model in the Browning Line. Japanese production began in 1976, all before then were Belgian. A few custom guns were made in Herstal after 1976, but they were exceptions and special commemoratives.
Your serial number indicates that your Browning light twelve was made in the year 1955.
You will have to contact Browning to find out.