I don't think he looks much like an oldenburg at all, but generally he doesn't actually look badly put together, I see potential there, but he has to learn how to carry himself.
Needs a lot of the right type of muscling; right now it he's got a pretty poor topline. In the riding pic his stride seems really short and he's hollow...hard to tell if he's got a straight shoulder or poor fitting tack. Smidge long in the back, smidge short in the neck. He's a cute horse; IF he has a decent shoulder and good legs and feet, I think he'd be a nice all-arounder. Encouraging that he's been ridden AND driven.
By the way, what is the asking price?