Scribes:

Robert J Matthews (1992): “The manuscript shows that Oliver Cowdery was the first, serving between June and October 1830; he recorded an introductory revelation (Moses 1) and the translation of KJV Genesis 1:1 to Genesis 4:18. John Whitmer served second, from October until December 1830, recording the translation of KJV Genesis 4:19 to approximately Genesis 5:20. Sidney Rigdon was next, becoming the main scribe from early December 1830 until the translation was finished on July 2, 1833. He recorded most of the translation from KJV Genesis 5:21 to the end of the Bible, although others recorded small portions.”

Source

Joseph Smith’s New Translation of the Bible, 1830. Kent P. Jackson.

“Sidney Rigdon was called to serve as the Prophet’s scribe in December 1830 (see Doctrine and Covenants 35:20), and he served in that capacity until March 1832. His handwriting is the most common on the pages; more than half of the pages show him as the original scribe. Jesse Gause, who served as a counselor in the First Presidency with Joseph Smith and Sidney Rigdon, served also as scribe off and on in March 1832. Fredrick G. Williams replaced Gause in the First Presidency and as scribe on the New Translation. He began as scribe in July 1832 and continued until July 1833, when the translation was completed.”

Source

“New information is included in Joseph Smith’s New Translation of the Bible concerning the handwriting of the scribes. Frederick G. Williams inserted words in Genesis, John, Acts, Romans, and 1 Corinthians. Sidney Rigdon wrote a short revision of Jeremiah 18:8, 10, and 14. An unknown scribe’s handwriting appears on part of NT 2, folio 4, pp. 136, 139-42, 147-49.”

Source

Date of completion of the New Testament:

Letter from Joseph Smith Jr. to W. W. Phelps:  “You [W.W. Phelps] mention concerning the translation. I would inform you that they will not go from under my hand during my natural life for correction, revised or printing and the will of the Lord be done. Therefore you need not expect them this fall. Brother Frederick is employed to be a scribe for me of the Lord. We have finished the translation of the New Testament. Great and glorious things are revealed [in it.] We are making rapid strides in the old book and in the strength of God we can do all things according to his will. JOSEPH SMITH COLLECTION, Document 155, “letter dated July 31, 1832″.”

Source