Mosiah 8:6 - 8:10

Mosiah 8:6 Now, as soon as Ammon had read the record, the king inquired of him to know if he could interpret languages, and Ammon told him that he could not.

After Ammon had read the record of King Limhi’s people, the king asked if he could interpret languages? Ammon replied he could not.

Mosiah 8:7 And the king said unto him: Being grieved for the afflictions of my people, I caused that forty and three of my people should take a journey into the wilderness, that thereby they might find the land of Zarahemla, that we might appeal unto our brethren to deliver us out of bondage.

King Limhi told Ammon that not to long ago, he had sent out 43 men to find the way to Zarahemla to get help against the Lamanites.

Mosiah 8:8 And they were lost in the wilderness for the space of many days, yet they were diligent, and found not the land of Zarahemla but returned to this land, having traveled in a land among many waters, having discovered a land which was covered with bones of men, and of beasts, and was also covered with ruins of buildings of every kind, having discovered a land which had been peopled with a people who were as numerous as the hosts of Israel.

The group got lost and were unable to find the city. However, they did find a land that was covered with many lakes. In this land they discovered the ruins of buildings and of the bones of men and animals. It appeared to this company of searchers that the land was once filled with a very large population but they were now all dead.

Mosiah 8:9 And for a testimony that the things that they had said are true they have brought twenty-four plates which are filled with engravings, and they are of pure gold.

To convince the people upon their return of what they had found in this land of many lakes, they brought back with them 24 plates of pure gold that they surmised contained a record of the land and its people.
[I’m sure the Lord planned for the record to be found and that whoever had the last change of the 24 plates was inspired to place where it they could be found.]

Mosiah 8:10 And behold, also, they have brought breastplates, which are large, and they are of brass and of copper, and are perfectly sound.

Along with the 24 plates, the party brought back body armor such as breastplates made of copper and brass. They were in very good condition. The people must have been of larger statue than the people of Limhi as the breastplates were bigger than there own.
[Being perfectly sound must have meant that they were not very old.]