It doesn't sound like it was rebuilt, it sounds like the entire axle assembly was replaced.
You could have a blown hub seal which will get it all over the inside of the wheel. That's my guess since the centrifugal force spreads it around. A leaking swivel seal just drips on to the wheel. Of course if the swivel seal is leaking a lot then it can look like a bad hub seal then check it frequently.
Get a couple cans of brakeclean and spray the swivel down good.
Also look up in behind the wheel and see if it's all over your rotor, pads and inside of the wheel. If it is, then it's the hub seal.