[editor-surveyor]

"I read one commentary that claimed that Shem may actually have been Melchizedek"

Melchizedek was the preincarnate Savior.

[what's up]

Yes, I personally believe that Melchizedek was a Christophany.

However, I find it interesting that the chronology finds it possible that it COULD have been Shem; that is, that he may have been alive at the time.