1998 defender front diff problems

Hi Guys,

Im new to this site and already have a problem with my sons 90 i towed him home late last night with my trusty disco 300tdi. ok lost all drive but i have looked under and the front prop is turning
so my question is what can i expect to be replacing?and which diffs my fit in there td5 disco 200/300 ect or do i have to find a second hand unit from a 300tdi of the same age 98?.
I have managed to move the car backwards by engageing diff lock but its a bit hit and miss as the linkage is all sloppy where as there is no low range i guess the linkage has came off i will need to look at that aswell i guess.
any help will be very much apprieciated ...Many Thanks

could be diff drive member or cv any 4 bolt flange 24 spline (300 tdi)
diff from d 1 or defender or d2 will fit

Many thanks for that better get on ebay and start looking...Thanks again mate..