What year was JC Higgins model 20-12GA 583.60 made?

The JC Higgins Model 20-12GA 583.60 shotgun was produced in the late 1950s to early 1960s. Specifically, it is commonly associated with being manufactured around 1961. JC Higgins was a brand sold by Sears, Roebuck and Co., and the model number indicates it was a product of that era.