Olaf Carl Seltzer, Blackfoot Scout, watercolor, 8 x 6. Estimated: $6,000-$9,000. ← Previous Olaf Carl Seltzer, Blackfoot Scout, watercolor, 8 x 6. Estimated: $6,000-$9,000. Olaf Carl Seltzer, Blackfoot Scout, watercolor, 8 x 6. Estimated: $6,000-$9,000.