You should focus your efforts on Unvanquished Client, because 450 strings in Unvanquished Gamelogic are being rewritten. (Mainly admin commands and strings you get when you connect to a server: %s connected, %s disconnected, etc).
UPDATE:: You can begin translating Unvanquished Gamelogic. You will see a new type of string: $1$, $2$, and $3t$. Just copy those exactly. We will substitute playernames and various other text in there.