You did not provide a serial number. You will have to call Browning.
Your Browning auto-5 shotgun with the prefix of 70s to the serial number identifies that your shotgun was made in Belgium for Browning in the year 1970.
Entirely possible.
By the serial number.
Serial number 1
by the serial number on the bottom of the receiver
With the serial number that you provided,and assuming that we are talking about a browning auto-5 shotgun then your shotgun was made by FN of belguim for browning in 1909.
Your browning auto-5 shotgun was made by FN of belguim for browning in 1957.
It was made in 1949.
The 4G prefix to your serial number indicates that your Browning auto-5 light weight shotgun was made in Belgium for Browning in the year 1964.
Your sweet sixteen browning auto-5 shotgun was made by FN for browning in 1963.
You did not provide the serial number.