If your goal is appearance-related, you need to let go of scale weight as the arbiter of progress. (Think about it: If you could have exactly the bodytype you wanted, but you'd have to weigh only 150# to get it, why should you care?) Instead, focus on the mirror--that is, diet and exercise until your body looks the way you want it to look.
As an aside, so long as you are an "avid" runner, you will find it extremely difficult to gain significant amounts of muscle. This is not to suggest you should run less; in fact, I'd say frequent running + occasional lifting days is a good way to get the sort of slender 'swimmer's build' that you're seeking.
As s far as getting abs is concerned, you still have a significant amount of fat to lose before they will be visible. That said, I don't see a whole lot of abdominal musculature at this time. Here's my recommendations in this regard:
For physique purposes, the only abdominal-wall muscle we want to develop is the rectus
abdominis—the ‘six pack muscle.’ The rectus originates at the hip bone, and inserts on the lower ribs. So, when this muscle contracts, all it does is pull the rib cage closer to the hip bone (by flexing the lumbar spine). Thus, when you set out to work this muscle, that’s all you want to do—try and touch the lower margin of the rib cage to the pelvis. You do not want to flex at the hips; ie, change the angle between the legs and the abdomen. (So no sit-ups, and no leg raises!) In fact, you want to put yourself in a position such that the legs are completely removed from the movement. To accomplish this, I recommend crunches, but in a specific manner:
1) Place a flat bench lengthwise touching a wall.
2) Lie on the bench with your butt ~2 feet from the wall, and your legs extended with your feet resting up on the wall. (This position completely eliminates the quads from assisting in the movement.)
3) Cross your arms over your chest, tuck your chin a little, then try and touch the lower margin of your rib cage to your hip bones (it is a very short ROM).
4) After you have gotten as close as you can, lower yourself halfway back (ie, do not let your shoulders touch down), then crunch again. And again. And again…Each rep, think about trying to touch your ribs to your hip bones.
In terms of programming ab work:
--Work abs 5-or-so days/week. (Every other day is a good start.)
--Go for time, not reps. Start by doing as many crunches as possible in 5 minutes. Don't worry if you can't go 5 min straight--pause as needed, then get back to it. But the ultimate goal is to be able to go 5 minutes without pausing once.
Finally, your aesthetics would be helped considerably if you made delt work a priority during your weight workouts. I would recommend spending fully half your sets on delts, and the other half on everything else combined.