Possible Matches, I tried to specifically look for missing children due to the UID's estimated age. (More possible names are bolded)
William Verne Downey,
Clifton Patrick Leonard,
Johnny Lee Mills,
Walter Thomas Ackerson, Jeremy Doland Bright,
Joseph David Helt, Mark Joseph Himebaugh
Walter Thomas Ackerson, missing since 1990 from Oregon:
Agree: The height is within the same ballpark.
The face really, reeeaaally looks alike in Reconstruction 1. I don't know
what's up with the one on the right, it doesn't look like the one on the left.
Walter and the UID were apparently both in need of dental attention.
Contradictions:
Walter disappeared from Newport, Oregon, which is nowhere near where the UID was found.
Additionally, Walter was (supposedly) murdered and thrown into a bay that was (obviously) not near where the UID was found.
Walter was apparently beaten to death. Would those injuries not be visible?
"Johnny Lee Mills", missing since 1990 from Maryland Heights, MO:
Agree: Strong facial resemblance to the UID. Height also checks out.
Johnny, being an apparent runaway, could've made it to the area where the decedent's body was found and then die or be murdered.
The dental problems could be explained by Johnny running away and not having the money or time to fix them.
Disagree:
The location is way off, but there's more of a chance that Johnny would've somehow gotten to Massachusetts that Walter Ackerson.
Several bodies in the area where Johnny disappeared match his description, but they cannot be identified as Johnny's since he is technically unidentified himself (Alas, Johnny's given information was not real, what a horrible cycle. :banghead
Johnny may not be 13, all of the info he gave to the people at the runaway shelter he was staying was untrue. He looks a little younger to me.
Note: It's likely that the UID was a victim of child abuse/neglect. Just saying, it's something to consider due to the lack of dental work. Maybe the parents killed him and never reported him missing and he didn't have many other living relatives, kind of like the Precious Doe case a while ago.