Im thinking there might have actually been two tobis.
The current one who is apparently Obito is 30 years old or at least in body.
When Madara was resurrected he said he awakened the rinnegan shortly before his death and he or him,as Madara says, gave Nagato the rinnegan during the SECOND NINJA WAR.
The second war was over 40 years ago and Obito didnt exist. Its obvious that Madara had a sidekick in his plans but Madara died after Nagato got the rinnegan and before Obito was born.
Im thinking either a different Tobi or just Obito body control.
What do you think?
(Sorry the sloppy typing )