I have dealt with Mr. Barfield's notions about the Copper Scroll here and here. I stand by my comment in the latter post, in response to an earlier article:
The article also reports many claims about prominent named Israeli individuals. Notice, however, that it makes no claim that those individuals have verified the stories. At least one of them, Yuval Peleg, is no longer living. It gives us no reason to think that the author of the article has interviewed any of the living people to confirm the claims.But I do have something to add. I will not try to address all the problems with Mr. Barfield's notions, but one stands out. In the early part of his video (start at 1:45) Mr. Barfield refers to a book called Emekh HaMelekh, published by a Rabbi Naphtali Hertz (Bachrah) in 1648. The relevant section is actually a copy of a text called The Treatise of the Vessels which contains legends about the hiding of the Temple treasures from the Babylonians when the First Temple was destroyed in 587/586 BCE. I published the first full English translation of this document a few years ago.
The story of Mr. Barfield's supposed discoveries sounds wildly fanciful to me. The author of the article has not interviewed any specialists in ancient Judaism or the archaeology of ancient Israel for evaluations of the claims. As usual with these things, I will believe exactly as much of it as is verified by Mr Barfield producing some actual ancient artifacts, such as vessels of silver and gold; gems; and, ideally, the high priest's ephod and breastplate, and, of course, the Ark of the Covenant. And once the produced objects are authenticated by real archaeologists and other specialists, preferably in peer-review publications.
Mr. Barfield claims that this text tells the story of the writing of the Copper Scroll.
The Treatise of the Vessels does indeed tell about the writing of a list of the hidden treasures on a tablet. One version of the story does say that tablet was made of bronze. But there's a problem.
The legendary treasures recorded on this fictional tablet were the treasures of the First Temple, which was destroyed by the Babylonians in 587/586 BCE. The treasures of the Copper Scroll were probably real, and were possibly treasures of the Temple, but of Herod's Temple that was destroyed by the Romans in 70 CE. Everyone agrees, and the evidence is quite clear, that the Copper Scroll was produced in the late first or early second century CE. It has nothing to do with the First Temple or its treasures. It cannot be the bronze tablet mentioned in the The Treatise of the Vessels, which is probably just a legend anyway.
Mr. Barfield starts with this fundamental misunderstanding of the Copper Scroll and then goes on to present a detailed edifice of inferences that the Temple treasures are hidden in a sealed cave at the site of Qumran. The connection of the Copper Scroll to The Treatise of the Vessels is embedded in this edifice and he refers to it from time to time in the rest of the video.
It's not clear to me whether he could make his case without reference to The Treatise. It does seem important to parts of it. More to the point, this weak start at the beginning of his presentation makes it difficult to take any of the rest very seriously. But if Mr. Barfield wants to convince me or any other specialist that any of his notions are correct, he can do so by producing some of these Temple treasures, recovered in a scientific excavation and published in peer review venues.
I published my introduction and translation of The Treatise of the Vessels in Old Testament Pseudepigrapha: More Noncanonical Scriptures, vol. 1 (ed. Bauckham, Davila, and Panayotov; Eerdmans, 2013), pp. 393-409. For past posts on it start here (cf. here) and follow the many links. For the many past posts on the Copper Scroll, start with the same two links.