Average price for the rifle itself in VG condition is $75-$125. The scope could add some value depending on the type of scope. Worn rifles of course have less value.
Your serial number indicates that your Glenfield model 20 bolt action was made in the year 1980.
your marlin/glenfield was made in 1974.
20626860
With the serial number that you have supplied,your Marlin(Glenfield) rifle was made in the year 1980.
your glenfield was made in 1968.
write to marlin with any and all writngs/markings on reciever/barrel and serial numbers
Marlin made the Glenfield firearms, not Winchester.
1980.
Your Glenfield model 60 was produced in 1989.
With the serial number that you have supplied,your Glenfield rifle was made in the year 1973.
I found the value of a Marlin/Glenfield (similar serial) to be at about $2,700. I'm looking too, but that's the price I was able to find.
Your serial number indicates that your Glenfield model 25 was made in the year 1976.