U people still dont get it???
Why u making all these theory's about something when u have a live example ....
There are 2 people who were revived by edo which were very old .... Do u know who ??
Madara and nagato ... So nagato would be a good example for this ...
Nagato was revived looking like the way he was when he died ,v.old .. But what made him young is the renagun (i hope i spelled it right ) he used the rengun to absorb chakara and change it to some king of life form which made him from a 120 year old dude to a teenager (and i think thats one of the renagun ability or gio's ability)....
We all know madara had a rengun , and 1st hokage's sell had a great auto. Recovery , so all madara need to be young is time or huge amount of chakara to recover from ....
If any objection , plse give better reason or statement ...