I was very much impressed by the curious representation on this marble sarcophagus. There was no information that I saw apart from: Roman, 2nd century AD.
But a viewer brought what seems to be the ultimate answer: The 1935 Guide of the Museum mentions a fragment from a sarcophagus from Hierapytna in Crete from the II century AD where Horus with a hawk head and long hair is seated in one of the niches. In his right hand he holds a scepter and the sacred uraeus, symbols of his sacred nature and kingship. To his right a young worshipper heads to the god. On his head a double tip cap with an uraeus too. Next to the young man a small Apis bull with the sun disc between its horns. Next to him stands Isis. The long left side contains additional scenes. The sarcophagus is said to be the work of a Greek sculptor who clumsily reproduced Egyptian scenes that he did not fully understand. The four sides of the sarcophagus depicted scenes of worshipping of Horus, Isis and Osiris by a young man and a woman, likely aimed at portraying those buried within.