"Plate 23 or 24: Egyptian gods Ptah-Osiris-Sokar approach the baby sun god Horus"; from The Manners and Customs of the Ancient Egyptians Vol. 3 (1841) by John Gardner Wilkinson.
Is it possible that the Stone of Sokar, placed on the Hennu Barque, was a meteorite? The ancient peoples of the area may have witnessed the fall of such an object. The symbolism seen in the images of this post seem to suggest that it was a meteorite that fell, of a significant size, after travelling quickly through the heavens. Both Chladni and Kesselmeyer do not mention it. Based on the evidence here, I would place the witness fall sometime during or before the 19th Dynasty.
External Links:
Theban Tomb 286: "Scribe of the Table" from the 20th Dynasty; 3D Virtual Tour. Click # 12 in the tour to see the Barque of Sokar relief in the lower left. Another image of it.
Depictions of the Barque of Henu at the Louvre: Enveloppe de Cartonnage. and Masque-Plastron..
Sokar: article and reliefs at AMNTE NOFRE (Amentet Neferet).
Other Examples:
Fig. 2 de « Planche 13 Thèbes, Medynet-abou. Bas-Reliefs Sculptés Dans Les Galeries Est Et Sud Du Péristyle Du Palais. Antiquites Tome Deuxieme. »
« Description de l'Égypte » (1821) par C. L. F. Panckoucke. Paris, C. L. F. Panckoucke.
"Relief of the divine bark Hennu - Temple of Hathor at Deir el-Medina."
"Henu Barque Amulet" (~525-30 BCE).
"Mummy and Painted Cartonnage of an Unknown Woman" (~850-750 BCE).
With Hennu Barque (Horus Boat, Bark of Sokar).
"Cartonnage Mummy Case" (~50 BCE) showing the Henu Barque.
The boat of Sokar flanked by jackals (3rd century CE).
Brooklyn Museum, Charles Edwin Wilbour Fund, 52.128a-e. Creative Commons-BY (Photo: Brooklyn Museum, 52.128a_52.128e_PS2.jpg). Color and cropping edits.
"Solar Boat reliefs on the walls of the Temple of Horus in Edfu."
By getye1, stock.xchng. Image License Unknown.
Block Statue of Ipwer; the right side shows the sacred boat of Sokaris. 25th or 26th Dynasty.
Study for Plate 122 of Baron Dominique Vivant Denon's "Voyage dans la Basse et la Haute Egypte" (1802).
© The Trustees of the British Museum, CC BY-NC-SA 4.0 via https://www.britishmuseum.org/collection/image/241505001 Color edits.
Example at the Vatican (Forse da Medinet Habu. Inv. 22707.), too bad they hide it on the right...