Hi am trying to put a brake disc axle on the rear of my land rover 90 but want to stick to 10 spline as i have a locker in it. For the life of me i cant find a disco 200tdi axle near me with out them asking for £200 . So i have all the internals and brakes from one will they fit on to a 300tdi axle casing as theres one close to me for £30 and i have all the other bits for free thanks for any help.

Yes they should do. I recently fitted a 300tdi axle casing to an early 200tdi disco (Identical casing) The only thing I remember being different was the calliper bolts. Because the 200 was so early, it used imperial 6pt bolts, whilst the 300 used 13mm 12pt bolts. The 12pt bolts didn't fit through the holes on the calliper, but my local engineering place drilled them out slightly and everything else went together fine.