Outside of legalistic semantics when one says that an object ‘belonged’ to someone, the helmet in question here, for instance, it means the object was the personal equipment of that individual not that it was part of their inherited property. Otherwise every object discovered in Northern Greece dating to 479 BC or earlier might justly be described as once having belonged to Xerxes I! Such sophistry remains what Aristophanes saw it for all those years ago.
I am not aware of any great accumulation of Achaemenid material ever being found in Macedonia, on your logic we would have to conclude that Alexander never conquered the East. The greater part of the loot was probably melted down and, in any case, probably remained in Asia. Antipater, returning with the kings had to sneak away from his troops demands for payment; he would not seem to be returning with a vast treasury.
It is absolute and crass stupidity to extrapolate from the Roman conqueror of Egypt’s disdain for the royal House of Ptolemy that the Graeco-Egyptian subjects of these rulers shared that disdain,
‘an entirely modern and anachronistic notion’ if ever one were evinced.
Here are the sources I can find on Ptolemy’s motivation
This was the enclosure which contained the burial-places of the kings and that of Alexander; for Ptolemy the son of Lagus, forestalled Perdiccas by taking the body away from him when he was bringing it down from Babylon and was turning aside towards Aegypt, moved by greed and a desire to make that country his own.Furthermore, Perdiccas lost his life, having been slain by his soldiers at the time when Ptolemy attacked him and hemmed him up in a desert island. So Perdiccas was killed, having been transfixed by his soldiers' sarissae when they attacked him; but the kings who were with him, both Aridaeus and the children of Alexander, and also Rhoxanê, Alexander's wife, departed for Macedonia; and the body of Alexander was carried off by Ptolemy and given sepulture in Alexandria, where it still now lies — not, however, in the same sarcophagus as before, for the present one is made of glass, whereas the one wherein Ptolemy laid it was made of gold. The latter was plundered by the Ptolemy nicknamed "Cocces" and "Pareisactus," who came over from Syria but was immediately expelled, so that his plunder proved unprofitable to him.
Strabo XVII 1 8
This makes no mention of Ammon, only ‘greed and a desire to make [Egypt] his own. Thus your ‘all ancient sources’ evaporates. Also it would seem that the defiling of Alexander’s tomb was the immediate cause of Ptolemy Cocces’ expulsion, demonstrating popular feeling for Alexander’s divinity as late as the first century BC (this is thought to be Ptolemy X Alexander I Philometor).
Diod XVIII xxviii 2
When Arrhidaeus had spent nearly two years in making ready this work, he brought the body of the king from Babylon to Egypt.3 Ptolemy, moreover, doing honour to Alexander, went to meet it with an army as far as Syria, and, receiving the body, deemed it worthy of the greatest consideration. He decided for the present not to send it to Ammon, but to entomb it in the city that had been founded by Alexander himself, which lacked little of being the most renowned of the cities of the inhabited earth. 4 There he prepared a precinct worthy the glory of Alexander in size and construction. Entombing him in this and honouring him with sacrifices such as are paid to demigods and with magnificent games, he won fair requital not only from men but also from the gods. 5 For men, because of his graciousness and nobility of heart, came together eagerly from all sides to Alexandria and gladly enrolled for the campaign, although the army of the kings was about to fight against that of Ptolemy; and, even though the risks were manifest and great, yet all of them willingly took upon themselves at their personal risk the preservation of Ptolemy's safety. 6 The gods also saved him unexpectedly from the greatest dangers on account of his courage and his honest treatment of all his friends.
Whilst this does mention Ammon, though only Ptolemy’s decision NOT to take the body there, it also implies that political benefits did accrue.
Aelian,
Chap. LXIV.
Of Alexander dead.
Alexander, Son of Philip and Olympia, ending his daies at Babylon, lay there dead, who had said that he was the Son of Jupiter. And whilest they who were about him contested for the Kingdome, he remained without Burial, which the poorest persons enjoy, common Nature requiring that the dead should be interred ; but he was left thirty daies unburied, until Aristander the Telmißian, either through Divine instinct, or some other motive, came into the midst of the Macedonians, and said to them, "That Alexander was the most fortunate King of all Ages, both living and dead ; and that the Gods had told him, that the Land which should receive the Body in which his Soul first dwelt, should be absolutely happy and unvanquishable for ever." Hearing this, there arose a great emulation amongst them, every one desiring to send this Carriage to his own Countrey, that he might have this Rarity the Pledge of a firm undeclinable Kingdome. But Ptolemee, if we may credit Report, †† stole away the Body, and with all speed conveyed it to the City of Alexander in Ægypt. The rest of the Macedonians were quiet, onely Perdiccas pursued him ; not so much moved by love of Alexander, or pious care of the dead Body, as enflamed by the predictions of Aristander. As soon as he overtook Ptolemee there was a very sharp Fight about the dead Body, in a manner akin to that which happened concerning the Image [of Hellen] in Troy, celebrated by Homer, who saith that Apollo in defence of Æneas engaged amidst the Heroes ; for Ptolemee having made an Image like to Alexander clothed it with the Royal Robe, and with noble Funeral Ornaments, then placing it in one of the Persian Chariots, adorned the Bier magnificently with Silver, Gold, and Ivory ; but the true Body of Alexander he sent meanly ordered by obscure and private waies. Perdiccas seizing the Image of the dead man, and the richly-adorned Chariot, gave over the pursuit, thinking he had gained the prize. But too late he found that he was couzened, for he had not got that at which he aimed.
Makes the motive explicitly political and based on the prophecy of Aristander.
Pausanias I vi 3
[3] He crossed over to Egypt in person, and killed Cleomenes, whom Alexander had appointed satrap of that country, considering him a friend of Perdiccas, and therefore not faithful to himself; and the Macedonians who had been entrusted with the task of carrying the corpse of Alexander to Aegae, he persuaded to hand it over to him. And he proceeded to bury it with Macedonian rites in Memphis, but, knowing that Perdiccas would make war, he kept Egypt garrisoned.
Again no mention of a burial at Siwah.
And Pseudo-Kallisthenes has the intended burial place Memphis!
Then straightway they made him ready for burial, and they put him in the coffin and carried it on a wagon drawn by mules, and brought it to the city of Babylon of Egypt.' And as they were journeying therewith they arrived at Baremoun (Pelusion) and the people of Memphis and many of Memphis the people of the government of that city went out to receive the body of Alexander the king, the Macedonian, and they sang divine praises [unto him]. And as they were bringing him into Egypt and were carrying him round about from place to place and from district to district in the country, Sikises, the governor, and Kestes said unto Kinos, "Do not bury him here, but in the city which he himself founded, for it is meet that his body should lie in that city without fear. and without disturbance, and without fighting for no earthly king whatsoever conquered Alexander the king."' So Ptolemy built a tomb for him
[in Alexandria], and laid the body of Alexander the king in it.
Rule one check what the sources say: Ms O’Connor would do well to note that too!
It would be interesting to hear your arguments for thinking Alexander may have been in Nektanebo’s sarcophagus, maybe you could post your paper, she notes your work only by empty assertions and does not mention a single argument; this is not scholarship.
I thought the companions wore Boetian helmets?!