I suppose actually fitting a seat is the easy part.Should be no problem at all, considering they were originally designed for 3 up front, and I don't think they've changed much!
I actually don't have defender at the minute. I am looking for one preferably with 3seats. What i noticed is there is far more selection with of 90's with 2 seats than 3 seats up front. So i am wondering can i buy a 2 seater with 3 seats on the V5, and do the wee conversion with no hassle.There should be a seat belt anchor hole if you dig round, this should tell you all you need to know.