Ah didn't spot the question about the D1 or D2 axle, however, it will almost certainly be a D1 axle, not many D2 axles end up on Defender.
STC4382G will cover all the disco and 90 bearings.
Also, you CAN change the bearings in a D2 takes a bit of doing but quite possible, I even have the SKF bearing no. here somewhere!
Timken are the G part no I told him to get.