Manuscript by the Rebbe Rabbi Ya'akov Yosef of Ostroh,"Rav Yeiby", the Leading Disciple of the Maggid of Mezeritch ...

Manuscript by the Rebbe Rabbi Ya'akov Yosef of Ostroh,"Rav Yeiby", the Leading Disciple of the Maggid of Mezeritch and a Close Friend of Rabbi Pinchas of Koretz – Has Never been seen in Auctions – (the Only One in the World?)
Manuscript. Four pages (a folded leaf0 with novellae on the Kiddushin tractate. The novellae was printed in all editions of the book 'Rav Yeiby" (the first of which was printed in 1792 and the last in 2012).
An important expert in the field of manuscripts dates the manuscript to the 1740's, during which Rav Yeiby lived.
We tried, unsuccessfully, to find examples of Rav Yeiby's handwriting in order to compare it to the handwriting of this manuscript. However, there are several facts that indicate that the manuscript was indeed handwritten by him:
The fact that what is written in the manuscript was printed from beginning to end in the early book 'Rav Yeiby'.
The fact that the writer noted the date and place at the head of the manuscript but did not add his opinion of or commentary on the novellae indicates that he is the writer of the novellae.
The manuscripts end with the words "It is true and sharp" (Nachon Ve'Charif), which are typically used by the author in other places in his book 'Rav Yeiby'.
Erasures and additions: one of the lines of the manuscript, which appears in the printed version, is erased by a line. It is unlikely that anyone who copied the text would have dared erase a line of the author's holy novellae! In addition, there are slight textual variations between the manuscript and the printed versions, a fact which is not fitting of a copying of the text.
To conclude, due to the above, it can be determined that the manuscript was indeed handwritten by Rav Yeibi.

Rav Yeibi
Rabbi Ya'akov Yosef of Ostroh (1737-1790), who was called by the initials of his name 'Rav Yeiby' (Ya'akov Yosef ben Yehuda) was one of the greatest Hassidic Rabbis of the third generation. He was a disciple of the Ba'al Shem Tov and of the Maggid of Mezerich. He was a close friend of Rabbi Pinchas of Koretz. Rabbi Levi Yitzchak of Berdichev said of him that he was "a Divine man who can be called Holy". Many miraculous stories are told of him.
He became well-known after the publication of his book 'Rav Yeiby' – Torah novellae and novellae on 53 Psalms and on the Aggadot of the Talmud. The first edition of the book was published in Slavita in 1792.

Condition: Good. The margins are worn, which is typical of the age of the item. Folding marks.