A look at the Apple ‘Skankphone’, built before the original iPhone release 12 years ago
Prototypes usually have red colored PCBs.
If I remember correctly, you can see the PCB color of the M68 prototypes through the dock connector.
It is also conceivable that this was a prototype and it had a replacement case retrofitted which would explain why it has an FCCid.
There was also a case of a skankphone being lost and sold after it was loaned to a member of Cingular's senior management, that one wasn't a factory escape.