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. Auto 5's with poly-chokes, compensators and recoil pads (other than Mag 12's) will reduce value. Near mint guns and original box will command an extra premium. Recommend taking it to a gun shop for appraisal.
100-400 or so
Check the auction sites.
$350
100-1000 usd
0-400 usd
500 uSD
50-500 usd
Impossible to value with just the sn.
0-375 usd
50-500 usd
$89.99
50-500 USD or so