default sky ETA: Stupid EAxis (please read)

Is the sky you see in the game not called skysphere? I've made a default texture replacement for skysphere, and it's not taking no matter which method I use to construct the package.

This makes me think one of two things is going on:

1. The sky has been coded to resist default replacement.

2. The sky isn't skysphere. Skysphere is then either a lost item, or it's used for something weird, like thumbnail generation.

Has anyone tried this before? Any ideas? Bueller?

ETA: The answer is 2, and possibly also 1. I found the new sky, but, um, check out what a normal-method default replacement did. Normal method for me means only replacing the highest-quality image in a txtr file, and mipmapping the other sizes to point to the big one.

ETA #2: I did a replacement package with the full range of mipmapped images. One side of the sky cube changed. (I should note that it looks like the neighborhood sky and the lot sky are two different things, since one turned green and the other turned pink/tan - the gradient colors I'm using for this). :/ I'm going to check the txmt file list to see if perhaps I missed some. If not, I'm going to scrap this and leave my notes here for anyone else who wants to try this.

ETA #3: OK. I have been up and down the game files, and I cannot find anything that might be the txmt for the sky, or txtrs for the other sides. Everything's either obviously something else, or it was ambiguous and ruled out. Does anyone know how to find the parts of a package when EAxis has named it all sorts of different things?