I was looking for 4.1.2 download from Casio and came across this...http://www.casiogzone.com/us/support/
. if you 'agree' in the downloads/software section it shows a table with a few files for the commando version of 4.0 and a txt file for how to do it. The information in the txt file was more technical than what I understand. But seems like it will get you back to stock phone. Here's what is in the text file
=================================== How to setup the build environment. =================================== This document describes how to build a build for the C811. Please follow the steps below to complete the Build. 1. Download the Base environment from Code Aurora Forum (CAF) found at https://www.codeaurora.org/
The Manifest File is as follows: https://www.codeaurora.org/xwiki/bin/QAEP/
<Android releases> Date Tag / Build ID Chipset Manifest Android Version August 10, 2012 M8960AAAAANLYA153617 msm8960 M8960AAAAANLYA153617.xml 04.00.04 $ repo init -u git://codeaurora.org/platform/manifest.git -b release -m M8960AAAAANLYA153617.xml --repo-url=git://codeaurora.org/tools/repo.git $ repo sync 2. Overwrite the C811's open source environment with the environment downloaded in Step 1. 3. Add the (JDK) Java Development Kit's path to the environment variable PATH. example: $ export PATH=<JDK's install path>/bin:$PATH 4. Run the commands below: $ source build/envsetup.sh $ choosecombo release msm8960 user $ make clean && make -j8 Note: Ensure to match the last "-j8" to the Build environment. Caution: Please note that we cannot guarantee operation using images created with this build. ====================================================== (C) NEC CASIO Mobile Communications, Ltd. 2013, All rights reserved.
Hope that helps. Seems like a way to get there but then I'm not real sure about what I'm looking at.