Rifles and shotguns were not required to HAVE a serial number until the 1968 Gun Control Act. Many of the J C Higgins branded guns sold by Sears were made before then. And yes, it is perfectly legal in the US to own a gun that never HAD a serial number- but illegal to remove a serial number.
Your serial number indicates that your Glenfield model 20 bolt action was made in the year 1980.
Every Browning has a serial number on it. The location depends on the model.
With the serial number that you have provided,your Winchester model 88 lever action rifle was made in the year 1962.
Looking at Winchester models, there is nothing listed for a Model 90 with serial number 298032. They have Model 1890 in a slide action, Model 1900, 1902, and 1904 in a bolt action rifle.
With the serial number that you have supplied,your Winchester model 12 pump action shotgun was made in the year 1941.
With the serial number that you supplied,your Winchester model 1912,pump action shotgun was made in 1961.
With the serial number that you provided.Your Winchester model 88 lever action rifle was made in 1960.
Impossible to answer without the model, type of action and serial number.
With the serial number that you have supplied,your Winchester model 88 lever action rifle was made in the year 1966.
With the serial number that you supplied,your Winchester model 1912 pump action shotgun was made in the year 1916.
With the serial number that you have provided,your Winchester model 1912 pump action shotgun was made in the year 1923.
With the serial number that you have provided,your Winchester model 88 lever action rifle was made in the year 1959.