Winchester Model 12 Featherweight: Dating & Information

Question
Could you please date this model 12, 1806362F and tell me why it is so hard to find information about the featherweight

Answer
It was made between 1959-1962. I can't narrow it any further. In the grand scale it was a very small number of guns produced. Basically it was a slight variation in model 12 to save a little weight. Alloy instead of steel were used where it could be used. The entire model 12 was replaced in 1963 with model 1200.