I have a Savage 22 autoloader/bolt action, with plain stocks, that is marked 6 D with deluxe written under that. I have never seen that listed anywhere, but I wonder if the D stands for "dovetail" since the receiver has grooves to mount a .22 scope, kind of like the "S" has a receiver sight. I am guessing it is a late gun in the 60's. I got it used from my Uncle in 1968. Anyone have any information on this?