I went back to look over the .mat files I had packed up. In my own game I altered a couple of the .mat files to be rid of the faint dark lines that lie just above certain textures, but failed to make the same changes to the files included here.
I've updated the archive. If you don't want to download again, here's what to do, and do this also for the original mod files if not using mine:
In the "Materials" folder are five .mat files. Open all of them with your favourite text editor (Notepad is fine.) The line which reads
TextureCoordScale 0.0 0.0 1.0 1.0
should be altered to
TextureCoordScale 0.0 0.01 1.0 1.0
Changing that second "0.0" to "0.01" causes to not read the top 1% of the texture, or 2.56 lines on these 256 pixel textures. In other words, in the vertical direction horizontal lines 2.56 to 255 are sampled, not 0 to 255. This ensures that the bottom edge of the texture does not 'bleed' slightly into the top as when the texture is sampled from the very top edge to the very bottom edge.
When sampling a texture from 0.0 to 1.0, the opposite edges become essentially in contact, in a 'wrap around' manner. If one edge is empty, the other edge having pixels present can be partially sampled, showing up as a faint line under certain conditions of contrast.