KV62 is a real question on its own. Was it really the tomb for Tut-ankh-Amen?, was it the tomb for Nefertiti? or was it original intended for Eye as high official? With the farao Amenhetep III there seems to be a change of location to the Western Valley, why is unknown, but the fact is that in the Western Valley there are besides WV22 a lot of attempts to build tombs there, mostly from the Amarna period, so it could well be that Tut-ankh-Amen did chose this site for his tomb like his grandfather Amenhetep, while Eye, the gods father, chose as high official, a super noble of the highest class, afforded to built himself a noble tomb in the Kings Valley.
The young king only ruled for 9 years, and his sudden death at 18 surprised the court, probably his tomb at the WV was far from ready to receive the body, so it could well be that Eye made his tomb available for the funeral of the king. It can also be that the tomb was much larger than it is now and they cut off the rest of the passages by a wall, and finished the small tomb.
Eye carrying out the opening of the mouth ritual, giving notice that he was the only and rightful successor of the young king. As farao now in charge he decided to build a new royal tomb for himself at the WV23.
The mummy of Eye was never found nor identified, and was not among those of DB320 and KV35. Mysteriously a pummel of a walking stick bearing his name was found in the tomb of Nefertari QV66, but there is no clue why or how it got there.
Amazing is the fact, if you compare the vast collection at the Cairo Museum, how all these items fitted inside the tomb.