The answer is that you have to take the first 2 digits of you're serial number.
that is in you're case 11.
then use 2000 minus the 2 digits that you have and that is you're date of manufacturing.
with you 2000 - 11 makes 1989.
Voila.
The 20 indicates that your gun was made in 1980. Marlin did not checker the stocks on the 39a at that time period.
The letters AA identify the year of manufacture of your Marlin 39A golden Mountie as 1965.
1960
Do you have a diagram of how to tear-down a marlin origianal golden 39m
Your serial number indicates that your Marlin golden 39A was made in the year 1982.
1965.
Your serial number indicates that your Marlin Golden model 39A was made in the year 1974.
50-159 USD
With the serial number that you provided,your Marlin model 39M was produced in the year 1973.
You can look that up here http://oldguns.net/sn_php/marlinlookup.php
Your Marlin rifle was made in the year 1975,with the serial number that you have provided.
Your marlin model 39a golden was made by marlin in 1964.