You sound in better shape than me, but my 2 cents is to try to some high intensity running once or twice a week.
A while back I started doing 15 x 100m sprints a couple of times a week. I am slow, but would would sprint the 100m in around 15 seconds and then take the remaining 45 seconds to jog back. Repeat 15 times.
This workout and a few variations on a football field, sprint 40 yards out/back etc. helped me lose some fat around the waist/abdominal area that wouldn't drop off from mileage or diet.
This is obviously anecdotal, but some sprints or shuttle runs helped me and they may help you. High intensity/sprints seemed to do something for fat loss that lower intensity running couldn't do.