[Royal Wulff]

The two figures are similar to photos appearing individually in Dee Brown's "Bury My Heart at Wounded Knee". The male is Plate 3 (p. 35, my edition, also on cover) and the female (I dare not use another term) is Plate 2 (p. 19). I could scan them to pdf and send them to someone, but I have no way to host the images.

[Drango]

http://imageshack.us/
Free hosting site...

[PRND21]

[knuthom]

The guy on the left looks more like this:

Painted Cheyenne
It is not identical, but seems to be similiar. Maybe he evolved to using photos as a basis for his own compositions.

Nah, too much work for a fraud like Churchill. He probably did copy it exactly from somewhere else.