Depending on condition the 25-20 cal book value is around the $800 mark. Selling value in the last 6 months has been between $475 and 650.
Your marlin 336sc(standard carbine) was made by the marlin firearms company in 1950.
The J prefix to your serial number indicates that your marlin model 39A was made in 1952.
Early firearms in .22 caliber were not required to have a serial number. Your Marlin 81 falls into this time frame.
1980
Somewhere on the frame.
1975.
Many .22 caliber rifles made before 1968 did not have serial numbers. This would include your Marlin 100.
This Marlin 39A Mountie .22 Caliber Lever-action rifle with serial number R5077 was manufactured between 1957-1958.
1955 1955
1896
The first 2 numbers of your serial number indicate when it was made.In this case your Marlin rifle was made in the year 1971.
The value of a .22 caliber bolt action Marlin Model 20 rifle with a serial number 71377074 is between $100 and $400. The actual value varies greatly based on its overall condition and the potential buyer.