If you still want to attempt recovery, I can give you from a working W70 (using dd or ADB) before trying anything risky.
directory onto a microSD card, the tablet automatically detects and initiates the firmware update upon rebooting. Built-in Rooting eken+w70+v20+wm8850+firmware+link
Your SD card is either formatted incorrectly or the files are hidden inside an extra subfolder. Ensure wmt_scriptcmd sits in the absolute root directory. If you still want to attempt recovery, I