Thanks for the tips, but the Basic Guide is about modding the PC/Steam version of the game, and says nothing about modding the Android version. As per my post above, what I've done is simply edit INI files, but when recompiling the OBB file (the package that holds all game files for Android) I suspect I may have updated the TOC file (Android Table Of Contents file) incorrectly. Presumably this is causing the game (or Google Play Store?) to see the OBB file as invalid. I'd be grateful for any Android-specific guidance on updating the TOC file correctly. Thanks.