Browning can tell you how it left the factory, and the gun can be dated by serial number.
Around $5000.
Browning does not use those letters to designate engraving.
Wood and amount of engraving
The name is Superposed. Find this book - Browning Superposed: John M. Browning's Last Legacy by Ned Schwing
Your browning superposed was made in 1933.
100-10000 usd
With the serial number that you provided,your Browning superposed shotgun was made in Belguim for Browning in the year 1955.
Superposed
Your browning superposed was made in 1968.
With no other information; 100-10000 USD
Receiver
No, they are not.