Hi user37337 -
I am still unable to reproduce the issue on your asset from above. I am getting expected results in 4.7.6 and in 4.8.2.
For Testing I used a Standard Opaque Material set to unlit and a vertex Color node input into Emissive Color. I checked your normals in Maya and everything looks correct in the FBX. Can you think of anything else that you are doing with the meshes that are incorrectly rendering that you have not mentioned. I know it is a simple material but can you post a screenshot of it just for reference.
Thank You
Eric Ketchum