What you're missing is the reference, Revelation 22:16, where Christ is the Bright Morning Star. That almost certainly makes it of the first half of the 20th Century.

Leeneia's right, there's a 1971 Library of Congress copyright credit to The Native American Church for it. This in turn puts an absolute earliest copyright of 1918 on it, which was the year the Church became incorporated, although its roots as a Church date back to the 1880s and as a religion to the Native nations.