Made in 1964
100-400 USD depending on condition.
new in box lists as 600 lowest quality is 200
Gun was made in 1961. Value is 100 to 350 depending on condition.
Without the serial number, the question can't be answered
This gun was made in 1968 and should be worth around $250-$300 if in good shape and if is a 12 GA. If it is a 16 or 20 GA it will be worth a little more.
1976 is the year
The serial number indicates your gun was manufactured in 1966.
Check the receiver.
Made in 1952