The Restoration is for the "Last Time" not the "Next to Last Time"

In the allegory taught by Zenos the Lord has a vineyard which represents the world and the House of Israel is likened to an Olive tree with its branches. The story recounts the patient and loving efforts of the Lord to save and encourage the tree to bring forth good fruit. Toward the end of the story, after “a long time had passed away, and the Lord of the vineyard said unto his servant: Come, let us go down into the vineyard, that we may labor again in the vineyard. For behold the time draweth near, and the end soon cometh” (Jacob 5:29). When they go down this time they find that all of the trees of the vineyard have become corrupt and that none are producing good fruit. Not willing to allow the corruption to remain the Lord decides to make one final and intensive effort to save the trees.
 

Wherefore, let us go to and labor with our might this last time, for behold the end draweth nigh, and this is for the last time that I shall prune my vineyard (Jacob 5:62).

Wherefore, dig about them, and prune them, and dung them once more, for the last time, for the end draweth nigh. And if it be so that these last grafts shall grow, and bring forth the natural fruit, then shall ye prepare the way for them, that they may grow (Jacob 5:64).

And the Lord of the vineyard said unto them: Go to, and labor in the vineyard, with your might. For behold, this is the last time that I shall nourish my vineyard; for the end is nigh at hand, and the season speedily cometh; and if ye labor with your might with me ye shall have joy in the fruit which I shall lay up unto myself against the time which will soon come (Jacob 5:71). 

After a period of consistent and intense labor the efforts of the Lord’s servants were successful.

And it came to pass that when the Lord of the vineyard saw that his fruit was good, and that his vineyard was no more corrupt, he called up his servants, and said unto them: Behold, for this last time have we nourished my vineyard; and thou beholdest that I have done according to my will; and I have preserved the natural fruit, that it is good, even like as it was in the beginning. And blessed art thou; for because ye have been diligent in laboring with me in my vineyard, and have kept my commandments, and have brought unto me again the natural fruit, that my vineyard is no more corrupted, and the bad is cast away, behold ye shall have joy with me because of the fruit of my vineyard (Jacob 5:75).

For behold, for a long time will I lay up of the fruit of my vineyard unto mine own self against the season, which speedily cometh; and for the last time have I nourished my vineyard, and pruned it, and dug about it, and dunged it; wherefore I will lay up unto mine own self of the fruit, for a long time, according to that which I have spoken (Jacob 5:76).

Although the Lord and his servants had labored with the trees in the vineyard at other times before, this final effort was described by Jacob as “the day. yea even last time that the servants of the Lord shall go forth in his power, to nourish and prune his vineyard; and after that the end soon cometh (Jacob 6:2). 

Several points in the allegory are noteworthy. When the vineyard had become entirely corrupt and the fruit was all evil the Lord of vineyard took action with his servants to reverse this, but, we are told, this would be the last such effort and the last time that he would send servants to labor in the vineyard and nourish it and prune it. The prophecy says that eventually the branches of the trees, which represent the Lord’s people in the last days before his second coming, would not be forgotten or rejected, but would “grow and thrive exceedingly” however, as they grew, there would also be pruning. Some, the most bitter branches, would be cut off from the Lord’s people, but, and this is noteworthy, the Lord would not allow the pruning of the evil branches from among his people to exceed the strength and size of the good. In the"last time" the labor was to continue until they should grow, bear good fruit, and the bad could be entirely plucked off and cast away.

In the revelations in the Doctrine & Covenants, the Lord makes it very clear that the events described in the Jacob allegory refer to the work of Joseph Smith and those who were to labor with him.

For thou art called to prune my vineyard with a mighty pruning, yea, even for the last time; yea, and also all those whom thou hast ordained, and they shall do even according to this pattern. Amen (D&C 24:19).

For behold, the field is white already to harvest; and it is the eleventh hour, and the last time that I shall call laborers into my vineyard (D&C 33:3).

Wherefore lay to with your might and call faithful laborers into my vineyard, that it may be pruned for the last time (D&C 39:17).

Wherefore, labor ye, labor ye in my vineyard for the last time--for the last time call upon the inhabitants of the earth (D&C 43:28).

Therefore, tarry ye, and labor diligently, that you may be perfected in your ministry to go forth among the Gentiles for the last time, as many as the mouth of the Lord shall name, to bind up the law and seal up the testimony, and to prepare the saints for the hour of judgment which is to come (D&C 88:84).

For the preparation wherewith I design to prepare mine apostles to prune my vineyard for the last time, that I may bring to pass my strange act, that I may pour out my Spirit upon all flesh (D&C 95:4).

The prophecies in the Book of Mormon and the revelations in the Doctrine & Covenants place the restoration of the Lord’s Church during the "last time" that the Lord and his servants, including Joseph Smith and those ordained by him would go forth in the Lord’s power to labor in, nourish and prune the vineyard. The scriptures indicate that through the efforts of the Lord, the Prophet Joseph Smith and his fellow servants, God’s  people would be established, nourished and pruned until they would grow and thrive exceedingly. While these scriptures speak of a pruning away of the most bitter branches, they give no indication of any interruption of the latter day work, that the Lord would abandon his servants, reject the trees with which the Lord and his servants labored, or that they would become corrupt again. The Scriptures do not speak of a restoration of the Restoration. Rather they portray one continuous work, by the Lord and his authorized servants in bringing forth the natural fruit which will eventually culminate in the salvation of his people. A testimony of the Church of Jesus Christ of Latter-day Saints, presumes an appreciation for where the Church stands in the Lord's timetable to prepare the way before the Lord's Second Coming. The work spoken of in the Book of Mormon and the revelations is for the "last time" not the "next to last time."