Wrong Paint from Factory ?

Well numbers matching is a different category of checks to original paint. If the body numbers on a 1970 match the Vin on the dash, the VIN on the fendertag, and the VIN's on the motor and transmission then it is most likely correct.

The caveat is that the body numbers may have been transplanted onto a different body if the original one was deemed to difficult to repair.

Depending on the extent of the final restoration it may or may not be possible to know the color the factory painted the car if it differs from the tag. One body number is stamped into the rear package shelf metal just behind the driver side speaker cutout. If that portion has not ever been repainted, and it is the green, and the number matches the tag, that could document the color story.

If everything has been redone, and there are no traces of the original paint to prove it was green, then there really is no way to prove it.