Yeah, after I read the instructions. I started out doing the same thing you did- dropped the texture in, added the appropriate lines to the cfg file and jumped in the plane. Oops, black interior. The instructions-
"1. Go to your "SimObjects" folder inside FSX.
2. Locate the "Airplanes" folder.
3. Then the aircraft named "Carenado C185F Tundra"
4. Copy the folder named "Texture" and all files in that folder from the "Carenado C185F Tundra" main folder to your desktop.
5. Copy and paste the texture files found inside this zip named "texture.N016MM" into the temporary "Texture" folder you just placed on your desktop.
6. Overwrite any files that you are prompted to overwrite.
7. Rename the "Texture" folder on your desktop to "Texture.N016MM"
8. Move that folder back into the SimObjects/Airplanes/Carenado C185F Tundra model main folder.
9. Move the "thumbnailn016mm.jpg" from this zip to your Carendado C185F Tundra model main folder.
10. Copy and paste the config data below to your aircraft config file below the last similar entry with a space between.
11. Edit the [fltsim.X] part of the newly added config data you just copied to the next number in sequence.
12. Save the aircraft config file."
Since I already have the texture in the sim, I simply opened up the C-185 Misty 016 folder, and the Texture folder, clicked "select all" in the Texture folder, and dropped them in the 016 folder. Tell it NOT to over write. Worked for me.
LOL
Sue