I tried all the tools available that I've found
1-flash a zip package containing the the 3 backed up .img files in CWM Recovery mode;
2-downloaded cwm-lgog_e977-brazil_10b-modem.zip from the EFS and MODEM backup/restore tutorial and flashed the modem zip package (replacing the modem.img with the one from my phone extracted with adb) ;
3-flashing stock firmware;
But still null IMEI and no network signal. Is there anything else I can try? Maybe if I get a specific file from another E977 model?