Was the Seal of Prophethood found on the Prophet's back, peace and blessings be upon him, at his birth, or was it placed there after the splitting of his chest? And did a Jew see it in Mecca at his birth?

Scholars have differed regarding the time of the appearance of the Seal of Prophethood. Some say he was born with it, while others say it was placed during the splitting of his chest when he was among Banu Sa'd, or at the time of his prophethood, or on the night of the Isra'. Al-Zarqani held that the sealing occurred three times. Al-Suyuti mentioned the story of the Jew who foretold the birth of the Prophet (peace be upon him) and his attributes, including the Seal of Prophethood, and Al-Hafiz Ibn Hajar deemed it sound. The Seal of Prophethood was a sign by which the People of the Book recognized him. It was also reported that the two angels who split his chest were the ones who sealed him, but this contradicts what is stated in the hadith of Aisha. It was also said that the Seal was removed after his death, but its chain of narration is weak.