Digging into the Grim Fandango Remastered files...

[JohnnyWalker2001]

That sounds perfect.

Even just something to convert dds into mcb would be a dream right now, but a tool that allowed me distribute changes without stepping on anyone's legal toes would be fantastic. If it could take command line input, I could write a simple batch file.

GFRTexturePatch.exe texturename.dds materials.lab

If it finds an mcb with the same filename, it extracts it and dumps it in the working folder, and then converts the dds and replaces the previous mcb. If it doesn't find an existing mcb, it just converts it and dumps it in the materials.lab.

Something like that would be great!