Underwood began his lecture by discussing the overall agenda of the Joseph Smith Papers Project: to gather "all materials pertaining to Joseph Smith." As part of this, they sent a request through the Church Archives to hand over any Joseph-related document—a request that also included the First Presidency Vault. As a result, the Vault was catalogued and an interesting document was found: an early manuscript that served as a basis for the 1833 Book of Commandments. This volume contains the earliest manuscripts for literally dozens of the earliest revelations.
It appears that JS would dictate a revelation, they would write it down, soon afterward copy it into the Book of Commandments and Revelations (BCR). It is obvious that this volume was taken to Missouri by John Whitmer and used as a printer's copy for the Book of Commandments.
Though the discovery of this volume comes as a tremendous shock, we have had hints that such a collection exists. For starters, the Community of Christ has had in their possession several sheets that were torn out of the BCR, and many thought that they were a part of a much larger collection of revelations. Also, Ezra Booth wrote in 1831 about "the 27th commandment to Emma," hinting to the idea that there was a collection of revelations that he was speaking of.
So, what's new in the volume? First, it contains the revelation to Oliver, Hyrum, and Josiah Stohl to "go to Kingston…I grant unto my servant the privilege that he may sell a copyright through you"—the much sought after Canadian copyright revelation. It also includes the revelation, given after the section we know as D&C 77 and following the question & answer style, that Orson Pratt later referred to when speaking about the Adamic names for God, Christ, and man; it begins: "What is the name of God in pure language? Awman."
Another interesting insight in the volume is how it demonstrates the "composition" of several revelations. Many smaller revelations received on the same day would be combined together in the printed edition, and the manuscript would have something like "connected" written between them to show as much. This is especially the case with D&C 42, though Underwood gave many more examples.
According to Underwood, the most significant thing that can be learned from this volume is how the revelations were edited and revised. A great example of this is D&C 6, a revelation given to Oliver Cowdery. This section is known for its reference to Oliver's "rod," but it was not originally recorded that way. Instead of "rod," it was written "sprout." Instead of "rod of nature," it was written "this thing of nature." Another instance includes changing the phrase that Joseph had "right to translate" to Joseph had "sight and power to translate."
The entire article can be read here.