The Winchester model 1400 Mark II was only produced during the years 1968-1972.That is the time frame of your shotguns manufacture.
I currently bought a 1400 mark 2 20 ga. and while i was researching i came across this page. I found out that my gun was made between 1968 and 1974 at this site http://www.shootingusa.com/GUN_QUESTIONS/gun_questions.html copy and paste it. I dont know if your gun is a mark 2 or what but maybe this will help.
The Model 1400 (affectionately called the Mark I - my note) made its first appearance in 1964 using the Model 1200 slide action of a rotating, locking lug bolt and a gas valve system. In 1966, the Model 1400 was made available in with the new Winchester recoil reduction system.
The winchester model 1400 MK II was only made and so stamped between the years 1968-1972.
100-300 USD depending on condition
The Winchester model 1400 Mark II was so marked only from 1968-1972.This would be the time span of your shotguns production.
The Model 1400 (affectionately called the Mark I - my note) made its first appearance in 1964 using the Model 1200 slide action of a rotating, locking lug bolt and a gas valve system. In 1966, the Model 1400 was made available in with the new Winchester recoil reduction system.
I can say that the Winchester model 1400 was engraved MARK II in only 4 years of production.These years were 1968-1972.The markings signified that Winchester improved the action release,and the checkering was redesigned.Winchester dropped this marking starting in 1973.
To find the year that any Winchester gun was made, you just need to know which model it is and what the serial number is (the model number and serial number are stamped on the gun itself). . Then go to this website and it will tell you when it was made: http://oldguns.net/sn_php/winmods.htm
Means it was proof tested by Winchester.
E-gunparts.com
Mark Indigaro was born on September 17, 1965, in Winchester, Massachusetts, USA.