Value is too difficult to be accurate without seeing the gun. Condition which includes the amount of original finish and original configuration will determine value. Recommend taking it to a gun shop for appraisal.
100-1000 usd
100-1000 USD
50-650 usd
BT99
Japan
100-1000 USD depending on condtion and EXACT configuration, papers, box, accessories.
Value depends on the features of the gun, and the condition. Please see the link and look up your trap gun for a general idea of value.
2003
1971
1988
You must call Browning as the sn you gave does not follow normal convention.
If you go to browning,s home page there is a way to age your shotgun there.