Nobody's Child
So many questions! So many things to think about!
To start with, I don't think the Mrs. Cecil Johnson lead should be completely ruled out yet. If this boy really was born to a teenager who was described as "mentally retarded", that could explain his syndrome. They must not have had a proper diagnosis for mother or child back then.
Someone had to have been caring for him, right down to the plastic pants and Jumping Jacks shoes. How much did they cost back then, compared to now? Were they considered cheap, or on the expensive side?
The red striped shirt and the quilt. Had his favorite color been red?
Some abused children have had nice clothes, prescription eyeglasses, braces, and the like. This boy may have been no different in that, except that he was a toddler with special needs. His clothing and the choice of shoes SEEMINGLY implies that this boy had an active life and was taken out regularly - perhaps not as big a secret as the Boy In The Box had been to young "M".
If his passing was natural, perhaps his caregivers weren't able to afford a funeral, but had used money to spoil the baby some, not knowing how long he had to live, given his health.
How were they doing financially? Could they have pinched pennies to use the money for his final set of clothes he was dressed in? Why not a suit? Unless they wanted to send him off in his favorite clothes -- or, if he had already been wearing them, simply panicked and didn't think to change him out of his old ones.
When he passed, either accidentally or naturally, a good fraction of the sympathetic public eye would have been accusatory toward those they knew were closest to the child. Something had to be done, but he needed a quiet sendoff. "None of that dumping in the woods or in the trash. No need to be accused of not watching him properly..."
One could look up records for the Cecil Johnson family online. I wonder if anyone in the area still remembers them.
Another question - who worked with iron that they had knowledge of where to get weights like that from?