Yes it will. Careful which LT230 transfer box you get as some TD5 Disco2 didn't have centre diff lock fitted.
Yes the TD5 manual box is an R380, but it will not be a direct swap for a Tdi or V8 R380 box.
The speedo drive unit (the electronic jobbie on the Td5) just pulls out as per the old mechanical type, it even uses the same coloured drive gear (depending on what size tyres you have)
what advantage do you get from fitting a TD5 transfer box?