Thanks for the advice.
I've been back to the bloke with the axles and got the prop as well, so that prob is solved. 10 spline rear and 24 front should be ok, am I right in thinking the 10 is tougher?
If so, the rear is the best place for it. Incidentally, the 10 spline half shafts are thicker throughout, no swelling points for bearings etc.
I haven't got ABS as you say. However, and this is a good one, the bloody caliper bolts from the 300 don't fit the 200. Despite the calipers being the same, the threaded holes in the axles aren't. So its a call to LR in the morning for 4 of those!
I'm hoping to back up and running by Saturday, and totally expert in Disco rear drive trains!
Stu.