The 20 indicates that your gun was made in 1980. Marlin did not checker the stocks on the 39a at that time period.
the stock is what you use to hold the weapon by.
the tf11 only comes with a stock or it doesnt. you can not buy an extra stock for the gun.
Any good stock maker.
Theonespy is the best app for tracking. it's very helpful for you.
Mainly in the stock
Estate sale, garage sale, gun shop, pawn shop, gun show, stock shop
Try e-gunparts.com, gun shows, gun shops, custom stock makers.
Try these sources: Numrich gunpartscorp.com Jack First jackfirstgun.com Bob's Gun Shop gun-parts.com
Disassemble the gun, and replace the back cap with the stock or take it to a paintball store, and ask them to.
Have you heard about the internet? Start with google Search for Savage 220 A stock then click
It is the end of the stock as opposed to the end of the barrel end of the gun