Melchizedek could also be Shem, the son of Noah. See wiki article about Chazal. Shem was the King of Salem. Melchi, king and zedek, righteousness. Being blessed by his father Noah to carry on what it means to be righteous. The simple fact that he lived for 500 years after the Flood, and also the last living relative of Abraham, who was a direct descendant, Abraham knew who he was. But after 500 years, no one else would appreciate that fact, and it would seem Melchizedek had no father or mother as all the stories about Noah and the Flood had become cultural myths.
If there was a source of written and oral tradition before the Greek influence of philosophy given consideration to the reality of a time before the Flood, where Noah and Shem were actual humans, why are we still insisting on a non-flood event? The common understanding is that life came out of a universal body of water. Is that not indicative of a global Flood? The oldest “writings” can only go back to the Flood, and no further. The only pre flood civilization left in observable form, would be Egypt, but post flood Egypt seemed to have started over, and the pre-flood knowledge vanished.
This image or connection to a most high divine form led to the creation of all early religious endeavors, but no answers came of such attempts. I tend to think that even Jesus would not have had the body of the so called culturally accepted god. If Jesus would have associated with the outcast of the earth, then they would have been repulsed by a perfect body. It seemed Jesus fit right in, so more than likely, and in keeping with the fact that he physically endured every sickness and disease that can be inflicted on humankind, that is exactly how Jesus looked and existed in human form, yet did not give into temptation and sin against God. Jesus having a perfect body and God image while human, before he received a spiritual one after the resurrection can not be true. In fact Jesus’ divinity was kept secret, and even his miracles forgotten by the time he was sent to trial, and condemned to death. The first writings had to take this non-interesting human and make him acceptable to God, even before such an account would be acceptable to humanity. There was nothing about being God in the flesh, but about A human who was the actual God. Later the additional accounts filled in how God became flesh. The truth came out despite false accounts being passed around to paint Jesus as just a product of sinful humanity.
As pointed out earlier in this thread, the only humans with this God image after the Flood would have been any of the four wives of Noah and his 3 sons. We are not told anything about them, nor would this image neccessarily have been passed on genetically. Albeit Shem did live 500 years, and was considered as having an eternal, without human parents, existence. He was the last priest of the most high, as that was not passed on to his descendant Abraham. God did promise Abraham that his descendants would be blessed and chosen by God to carry out God’s blessings on earth. God made a covenant with Moses. God then came in the flesh, at the right time in history to allow a future restoration to the image that Adam lost. That was Paul’s message to the world. Paul said only in physical death would the God image be received.