I should've taken the time to expound on my post, if only briefly (which isn't easy for me, of course). Archaeologists have recovered a dizzying array of animal bones (and animal mummies) from the ancient Egyptian world, many of them deliberately and respectfully buried by mankind. This includes everything from elephants to shrews. And while countless baboons were interred or mummified, I can't think of any example of the bones of a gorilla dating to the pharaonic period. Were they even indigenous to Egypt at some time? Not that many of the baboons were—many of them were imported from farther south in Africa.
Think of the veritable army of gorillas it would've taken to assist with something like the Great Pyramid. Even if the gorillas numbered only in the hundreds, could humans have controlled them adequately?
Gorillas I think would have to have been imported, like the baboons, if there's any chance they ever were found in Egypt. I don't know if an army would be necessary, but indeed, significant numbers would be needed; on the order of at least fifty (which would amount to the equivalent in strength of approximately 200 humans). It would be a challenge, to be sure; it would be very difficult to capture and import that many specimens, particularly over long distances, and with the equipment available at the time. The only really feasible solution would be the capture of infants, and have them reared in Egypt, although this could be problematic given that a gigantic supply of food would need to be imported as well, given gorillas' diet is not endemic to Egypt, as I understand it. So, fifty or more infant gorillas, transported over hundreds of miles along with lifetime supplies of acceptable vegetation for all of them = extremely unlikely scenario. That, coupled of course with the noted fact that we don't see any evidence of these individuals, which would have needed to be cared for very intimately as they were raised, makes it appear as though it didn't happen.
Well, it was an interesting hypothesis whilst it lasted (certainly better than dinosaurs...), but I suppose we've just about laid this one to rest.