No two Millennium Falcons built for production of the films are the same. They built 2 for ANH (full scale profile and 5'), 4 for TESB (complete full scale, 32", 12", 2"), 2 for TFA (full scale profile and digital), and so far we know they've built s a new complete full scale for TLJ. That's not even counting interiors.
Apart from a reasonable approximation of the colored panel marking the weathering on each ship is unique. The battle damage is different. The greebles are different. It doesn't matter. You just try to get the right "look". That's all ILM went for.
The Falcon is as much a character as much as Luke, Han or Leia. Unlike Star Trek with it's alphabet soup of Enterprises there is only one Millennium Falcon and JJ better not blow it up.