Guys from 4pda.ru figured out method how to unlock this device!!! (mean cellular provider lock). If anyone who needs this instruction to be translated to English and posted here, I can do this. Translation of instructions is not an easy work, so I need at least a couple of voices (However one voice is enough for me) to start translating it ;)
Creating these folders will work only if stock ringtones are working correctly. After copying needed mp3 to "ringtones" folder you have to set this mp3 in sound settings as you ringtone. This is used only to eneble custom ringtone setting. Creating this folders in no way will affect anything else.
Thanx for your great work! Now I'm downloading 16.06 ROM, it seems that MD5 checksum is incorrect in first post (in goo there is different md5 for this file). Think you had not enough time to update md5 string in first post. Please check this when you get free minute.