Board Thread:Questions and Answers/@comment-61022-20160330220251/@comment-16461120-20160406133119

clearly says the Kingdom of Manhattan consisted of two parts, explicitly one " similar  to Earth-616" and one " similar  to Earth-1610".

This means we're left with the realization that the realities involved were in fact neither Earth-616 nor Earth-1610 like we thought, but rather whatever they were are now somethings unidentified, which merged to become Earth-61610, and the stark truth is that we may very well never know what the original designations of these similar realities were.