Note that this is not a reproduction of the actual document; it is a reproduction of a drawing of the document for the newspaper Al-Hilal in 1904.
<p>The original document is now kept in Topkapi museum, its state of preservation can be seen in <a href="//commons.wikimedia.org/wiki/File:Muhammad_letter_muqawqis.jpg" title="File:Muhammad letter muqawqis.jpg">this photograph</a>.
</p>
"LETTER OF THE PROPHET TO THE “MUKAUKIS,” DISCOVERED BY M. ÉTIENNE BARTHÉLÉMY; BELIEVED BY SEVERAL SCHOLARS TO BE THE ACTUAL DOCUMENT REFERRED TO IN THE TEXT. From the “Hilal,” Nov., 1904."
unknown (drawing is signed in lower left corner)
Margoliouth, D. S. (1905). Mohammed and the Rise of Islam (Third Edition.). New York; London: G. P. Putnam’s Sons; The Knickerbocker Press.