One more thing I did try this method but it also failed because my current version shows nothing? and I get error which mean wrong RUU. I think I need to flash the correct firmware before I restore the RUU.
There are instructions in the post to flash the full firmware zip. Make sure to issue 'fastboot flash zip 4.06.651.4_firmware.zip' two times, one right after the other. The first flash will update the hboot only and return an 'hboot pre-update error', the second flash will update everything else in the firmware zip.