Thanks for the help.
I've fixed the problem, I think (I've not actually been out yet), but I've swapped the bars around so the gap (and the levers, which is what I was banging my knees on) is at the front. the hand positions are about the same, except I now have the levers at the front, furthest away from me, which suits me, as this is where I tend to ride.
Oh, and Lolly pop, funilly enough, I added stubby bar ends in about the same place as yours (at the front and towards the centre). I used to have them like that when using flat bars and found them a great help.