How old is a model 126.2831 Sears Pellet gun?

The Sears (JG HIGGINS) model 126.2831 is a Crosman model 180 made for Sears. It was made in 2 variations. The first variant had a Crossbolt safety 1956-1959. The second variant had a die-cast trigger housing 1962-1967. This rifle is a .22 caliber pellet rifle, not a .177 caliber rifle or BB rifle. In poor condition it is worth $25. In good - $80 to $105. In Excellent - $125 to $155. Like New- $180.

See the link below for the owners manual.