"Other sheep:"
Christ came over and.......did the same things he already did in the New Testament, including an almost verbatim repeat of the Sermon on the Mount.
That gives us no new information (doctrine) about Jesus/the nature of God/the meaning of life/"the gospel" that was not available from the Bible and/or mainstream Protestantism.
"Hebrews -------> Native Americans:"
Several explorers, especially during the 17th and 18th centuries, claimed to have collected evidence that some of the American Indian tribes might be descended from the Ten Lost Tribes. Several recent books and articles have focused on these theories.
The belief that some American Indians were a Lost tribe of Israel goes back centuries and includes individuals like the 1782 President of the Continental Congress Elias Boudinot and Mordecai Noah, the most influential Jew in the United States in the early 19th Century.
http://en.wikipedia.org/wiki/Ten_Lost_T ... an_Indians
Also, I have already given an example of another denomination that uses the Book of Mormon as scripture, yet has a vastly different understanding from the LDS Church of what "the gospel" is and what "the plan of salvation" is.
So, again, what doctrines about the nature of God/Christology/etc. that are unique to The Church of Jesus Christ of Latter-day Saints are found within the pages of the Book of Mormon?