Is the narration that includes the will of Ali ibn Abi Talib (may Allah be pleased with him) regarding the shroud, upon his death, and concerning the treatment of his killer, authentic?

Shaykh Abd al-Qadir al-Arna'ut declared the chain of transmission (isnad) of the narration related by Ibn Zabr al-Rab'i in his book Wasaya al-Ulama 'inda Hudur al-Mawt (Counsels of Scholars at the Time of Death) to be weak. This narration, transmitted on the authority of Al-Sha'bi, recounts the counsels of Ali ibn Abi Talib after he was struck. The weakness in its chain lies in the presence of 'Amr ibn Hashim, who is considered "lenient in narrating hadith" (layyin al-hadith), and also because Al-Sha'bi only heard a single letter from Ali. Ibn Abi al-Dunya also narrated parts of this tradition in his book Maqtal Ali ibn Abi Talib, and its chain of transmission contains the same two defects.