Here is Ron Wyatt's testimony about discovering the Ark of the Covenant. He seems to share a beautiful testimony with desire that souls will be saved - very sincere, humble and not sensationalist, sharing with calm reason. He relates that angels directed him that the 10 commandments should be shown to the world in the time of the Mark of the Beast, and that it is currently still under Calvary.
It makes sense to me that this would be true, and seems to match Ellen White's description of the matter. Of course those who hid the Ark wouldn't have had any way of knowing that they were hiding it under the hill that would become Calvary later, but God could direct them (http://www.whiteestate.org/issues/Ark.html);
"Before the temple was destroyed, God made known to a few of His faithful servants the fate of the temple, which was the pride of Israel, and which they regarded with idolatry, while they were sinning against God. He also revealed to them the captivity of Israel. These righteous men, just before the destruction of the temple, removed the sacred ark containing the tables of stone, and with mourning and sadness, secreted it in a cave where it was to be hid from the people of Israel, because of their sins, and was to be no more restored to them. That sacred ark is yet hid. It has never been disturbed since it was secreted."--4SG 114, 115 (1864);1SP 414 (1870); SR 195.
"With His own finger God wrote His commandments on two tables of stone. These tables were not left in the keeping of men, but were placed in the ark; and in the great day when every case is decided, these tables, inscribed with the commandments, will be placed so that all the world will see and understand. The witness against them will be unanswerable."--Letter 30, 1900 (19MR 265).
"The precious record of the law was placed in the ark of the testament and is still there, safely hidden from the human family. But in God's appointed time He will bring forth these tables of stone to be a testimony to all the world against the disregard of His commandments and against the idolatrous worship of a counterfeit Sabbath."--Ms 122, 1901 (1BC 1109).
"When God's temple in heaven is opened, what a triumphant time that will be for all who have been faithful and true! In the temple will be seen the ark of the testament in which were placed the two tables of stone, on which are written God's law. These tables of stone will be brought forth from their hiding place, and on them will be seen the ten commandments engraved by the finger of God. These tables of stone now lying in the ark of the testament will be a convincing testimony to the truth and binding claims of God's law."--Letter 47, 1902 (7BC 972).