DC Special 6 (Jan/March 1970) is the last issue to have the giant logo, as well as being the last one to have an extensive framing sequence. The only weakness is that the lovely Neal Adams cover hints at the twist ending.
The issue opens as two young boys meet an old man chopping wood. He winds up telling them a bunch of stories about the old days, which enable the reprints of Tomahawk, Daniel Boone, Kit Carson, Davy Crockett, Buffalo Bill and Pow-Wow Smith. Gil Kane does the art on the framing pages.
The man and the boys pop up briefly between each of the stories, and then close out the issue with some new pages. While everything in the framing story seems to be set in the present day, a native child, and then his father, show up. The men and boys are shocked to see them, wearing traditional garb and firing arrows.
But then the big twist happens. The whole story has been taking place on a different planet. The whites are colonizers, and the natives are descendants from Earth natives who landed there long ago. The whites ask the native to allow them to live side by side in peace. The natives fall for this, the way they did long ago. It does not bode well for their future...