Mirror Halves Problem

Hi, I have a problem with my model. When I mirror one half or scale it -1 on the x axis it becomes darker (I’m not talking about normals, I always recaulate them and I have removed doubles even with large merging distances but nothing changes) than the other and I have been struggling with this for a long time. I hope you will able to help me. You can find the .blend file attached.

Attachments

Help.blend (627 KB)