В итоге после установки свеженькой LTC 12.4 получаю - английский интерфейс, а при попытке починять...
,,,@ubuntu:~$ sudo localedef ru_RU.UTF-8 -i ru_RU -fUTF-8
,,,@ubuntu:~$ sudo locale
LANG=en_US.UTF-8
LANGUAGE=en
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC=ru_RU.UTF-8
LC_TIME=ru_RU.UTF-8
LC_COLLATE="en_US.UTF-8"
LC_MONETARY=ru_RU.UTF-8
LC_MESSAGES="en_US.UTF-8"
LC_PAPER=ru_RU.UTF-8
LC_NAME=ru_RU.UTF-8
LC_ADDRESS=ru_RU.UTF-8
LC_TELEPHONE=ru_RU.UTF-8
LC_MEASUREMENT=ru_RU.UTF-8
LC_IDENTIFICATION=ru_RU.UTF-8
LC_ALL=