Regarding this post - I found this:
Rav Yisrael Gellis worked as a reporter for the Israeli Yated and other Israeli media outlets and was a close confidant of the Ponovezher Rosh Yeshiva Rav Elazar Menachem Mann Shach who, perhaps aside from the Vilna Gaon, left the most hostile legacy towards Chabad in the history of the organization’s opposition. Rabbi Yisrael Gellis interviewed Rav Shach’s son, Dr. Ephraim Shach, on November 10, 2001, just one day following the shivah for his father, the rosh yeshiva, for close to four hours in his home. Among the topics covered was the rosh yeshiva’s hostility to Chabad and the Rebbe. Rav Dalfin spoke to Rav Gellis on October 15, 2020, and he shared two positive stories that Dr. Shach had shared with him in the course of the interview. Rabbi Shach instructed his son, who was traveling to New York, to visit the Lubavitcher Rebbe and tell him, in his name, that he has no personal grievances against him; rather, he opposed certain shittos of Chabad that had compelled him to come out as strongly as he had. The Rebbe replied that he understood what his father said and proceeded to ask him several questions. He then gave Ephraim a dollar for himself and one to give to his father, which he did.
Another time, Rabbi Shach, in a conversation with Reb Yaakov Gellis, the father of Reb Yisrael, lauded the Rebbe. The senior Rabbi Gellis had authored ten volumes on the Torah portions of Bereishis and Sh’mos called Ba’alei Tosafos al HaTorah based on the manuscripts of the Ba’alei Tosafos. The father asked his son, Yisrael, to accompany him to Rabbi Shach because he wanted to give him his sefarim. The son accompanied his father to Rabbi Shach and the rosh yeshiva praised his work and thanked him for bringing him the sefarim. As they were leaving the rosh yeshiva’s office, Rabbi Shach told the senior Rabbi Gellis, “Ich hob fahr aich ah ba’al battishe eitzah,” I have practical advice for you. It would be a good idea to give these sefarim to the Lubavitcher Rebbe due to his expertise in Rashi and Tosafos from their original manuscripts and he would truly appreciate your work. His father looked at the rosh yeshiva with a look of bewilderment, since just a day earlier he had publicly lambasted Chabad! Rabbi Shach sensed his bewilderment and said, “The fact that I have issues with Lubavitch does not mean I have any personal issues with the Rebbe of Lubavitch.” He then continued, “He is a big expert on handwritten manuscripts and it is proper for him to see your books. You will benefit from showing him what you wrote.”
Two days later, the younger Rabbi Gellis was onboard a flight to New York with the ten volumes in tow in order to share them with the Rebbe just as the Ponovezher rosh yeshiva had advised. He spent Shabbos at the Park House hotel in Boro Park and on Sunday, he went to see the Rebbe who was distributing dollars. He was brought to the Rebbe by Rabbis Berke Wolf and Tuvia Blau. He placed the ten books on the table and the Rebbe remarked that he had already procured nine of them with the exception of the volume on Vayakhel and Pekudei and thanked him for coming all the way to bring him the sefarim. The Rebbe gave him a dollar for himself, a dollar for being the shliach to deliver the books, a dollar for his father, and one more for the Ponovezher rosh yeshiva’s gedank idea, for recommending that he bring the sefarim.
He returned to Eretz Yisrael several days later and brought the dollar directly to the rosh yeshiva’s house. He said thank-you and put the dollar underneath his Gemara. Yisrael Gellis said that Rabbi Shach’s grandson, Yissachar Ber Bergman, holds on to that dollar in his wallet.
