"Only" revolver would come closer to describing the Sentinel series. Personally, I can't remember there being a "standard". I thought that all Sentinels were marked "deluxe", though I could well be wrong. Wait until you find one in gold, sky blue or pink. Those were strange. The Double Nines were part of the very same series, simply with different cosmetics to resemble a single action. As a whole, their greatest shortcoming, in my opinion, was the lack of adjustable sights. They were a great fixed sight "kit" gun, with their aluminum frames. We still have one in the family and it functions perfectly. The Crusader series of centerfires hardly counts as a "series" since their total production comes closer to dozens than it does to thousands.