NO DOCUMENT OF ACTUAL SIGNATURES
The CES Letter seeks to imply that the witnesses didn't actually agree with being witnesses no longer have the original document. Nothing could further from the truth. Let's explore this.
CES LETTER CLAIM
No Document of Actual Signatures
CES Letter, Page 99
What a conspiracy theory! There is zero evidence for this theory and is a rather straightforward answer to why we don't have the original signatures. The original manuscript to the Book of Mormon was put in the cornerstone of the Nauvoo House which, unfortunately, resulted in much of the original manuscript being damaged or destroyed. This included the original signed testimony of the witnesses. It's estimated only 32% of the original Book of Mormon manuscript remains.
The surviving manuscript is the printers manuscript and it's in Oliver Cowdery's handwriting. Thus, we can take his signed testimony as valid. Additionally, both David Whitmer and Martin Harris separately affirm their original testimony.
Let's go one-by-one:
The surviving printers manuscript (pictured above) was written by Oliver Cowdery.
"I also heard the voice of God from heaven, commanding me to bear record of the things that I saw, and what is written of the three witnesses in the fore part of the Book of Mormon is true, and I dare not deny it, lest the power of God should consume me."—EARLY MORMON DOCUMENTS 2:384
Apostles Orson Pratt and Joseph F. Smith visited David Whitmer in Richmond Missouri on September 7-8 1878. During their conversation, David Whitmer affirmed that he signed the original manuscript.
Joseph F. Smith's Diary
The fact also appeared that the names of all the witnesses were subscribed in the handwriting of Oliver Cowdery. When the question was asked David Whitmer if he and the other witnesses did not subscribe their own names to the respective testimonies, he replied that they did. Then he was asked, 'Where are the original documents?' That he did not know, but supposed Oliver had copied them, but this was an exact copy.— EARLY MORMON DOCUMENTS 5:47
Joseph F. Smith's Letter to John Taylor
"We found that the names of the eleven witnesses were, however, subscribed in the handwriting of Oliver Cowdery. When asked if he and the other witnesses did or did not sign the testimonies themselves, Mr. W. replied, ‘each signed his own name.’” The interviewer then asked, “Then where are the original signatures?” David responded, “I don’t know, I suppose Oliver copied them, but this I know is an exact copy.—Letter to John Taylor and the Council of the Twelve, published in the Deseret Evening News, Nov. 16, 1878 (EMD 5:49).
The Improvement Era (1899)
Father David Whitmer was asked if *the three witnesses* signed their own names to their testimony to the Book of Mormon? Father Whitmer unhesitatingly replied with emphasis: ‘Yes, we each signed his own name.’ ‘Then,’ said the questioner, ‘how is it that the names of all the witnesses are found here … written in the same hand-writing?’ This question seemed to startle Father Whitmer, and, after examining the signatures he replied: ‘Oliver must have copied them.’”—"The Original Manuscript of the Book of Mormon,"Improvement Era 3/1 (Nov. 1899): 61–65.
Further Insight on the Printer's Manuscript:
James Henry Moyle, who interviewed David Whitmer, added the following insight about the surviving printers manuscript.
 James Henry Moyle, diary, 28 June 1885; in Vogel, Early Mormon Documents (Salt Lake City, Signature Books, 1996–2003), 5 vols, 5:141.
In light of the numerous documented testimonies from the both the Three and the Eight Witnesses, this criticism is shallow and irrelevant. Click here for more quotes by the witnesses