Stocks were available in; Straight, full (capped) or semi (capped or uncapped) pistol grips. The DS I believe was only available in uncapped semi pistol. The Capped full grip seems to me to be the most commonly encountered in other grades.
There was listed a "One Thousand Dollar Grade" going down from there were; Optimus, AA, A thru I inclusive with the DS being identical to the I. The Ds was the one actually listed in LAC catalogs with the I apparently being mostly sold through SD&G outlet.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra