NOTE: I've done the texture for the NGX Prepar3D version! It will work in FSX probably, but no clue will it look identical like in Prepar3D.
Choose the version you prefer and copy the file to ...SimObjectsAirplanesPMDG 737-800NGXtexture.vc... or to texture.vclow if you are using low res cockpit.
I've included original file, in case you forgot to back up. :)