B. H. Roberts calls the Book of Mormon "ancient" and a "translation."
B. H. Roberts, Speech, M. I. A. Jubilee Conference, June 7, 1925, in "Jesus is the Christ—The Eternal God," Liahona: The Elders' Journal 23, no. 2 (July 14, 1925): 30
"We stand for absolute faith in the Eternal God, revealed in Jesus Christ."
That comes from our Book of Mormon, and is part of the preface of that ancient record, but it has always been published upon the title page of the translated work. That preface explains that this record has been brought forth and preserved, that it might lead to the convincing of "the Jews and Gentiles that Jesus is the Christ, the Eternal God, manifesting himself unto all nations." This is the primary purpose of this American volume of sacred scripture, the Book of Mormon, not to testify merely to the divinity of Christ. That is quite generally conceded, speaking now of Christendom. Being divine is one thing, but being Deity, the Eternal God, is something more than being divine.