Interesting Letter of Biography of Rabbi Kook

Letter to Rabbi Ya’akov Rabinowitz of Lutzen [Rabbi of Rabbi Kook in his youth and relative]. Contains unknown details regarding Rabbi Kook. [Vilkaviskis, 1885].
Unidentified writer, relative of Rabbi Ya’akov Rabinowitz, who announces his engagement to daughter of Rabbi Yehuda Yitzchak HaLevi Segal of Vilkaviskis. He also mentions common relatives: “…our friends and relatives… our relative Dover…”.
On margins of letter, the writer adds: “I was informed that our relative Rabbi Avraham Yitzchak HaCohen became engaged to daughter of Av Beit Din of Ponevezh; I would like to know whether this is true as well as additional details since I was very happy to hear that he was miraculously saved from Av Beit Din of Toretz”.
Recipient of letter, Rabbi Rabinowitz (1856-1919), son of the Ga’on Rabbi Mordechai Gimpel Yaffe Av Beit Din of Razina. Merchant and manager of Jewish bank in town of Lutzen, among prominent community activists in Lithuania, who was also known as exalted genius in Torah.
The Ga’on Rabbi Avraham Yitzchak HaCohen Kook who was his relative [see attached material] spent time with him in his youth and was his disciple [in his letters Rabbi Kook refers to him as “my rabbi and mentor”].
This letter, which was written approximately two months following engagement of Rabbi Kook to daughter of the Aderet [Rabbi Eliyahu David Rabinowitz-Teomim] Av Beit Din of Ponevezh, contains unknown details pertaining to former engagement of Rabbi Kook to daughter of Rabbi of Toretz [apparently Rabbi Mordechai Beharif author of Darchei Mordechai] which was annulled.
[3] pages. 20 cm. Good condition, stains and wear. Folding marks.