Body development - swimming versus dryland

Hey all. I've been doing a lot of exercise lately across a wide variety of disciplines. One of the things, in fact the main one, I'm trying to achieve is a swimmer's physique - nothing new there, I suppose :) I'm fairly close but am really uncertain about one thing. I tend to be smaller than I want rather than heavier- it's a real struggle to build the upper body I'm looking for as opposed to, say, losing fat. I'm just naturally thin. For my latest regimen to build up chest, back and shoulders, I thought I would do sprinting pyramids in the pool, increasing max every week. So it would go like this: Monday - *** - sprint 1 lap, rest, sprint 2 laps, rest, sprint 3, etc. up until say 5, then back down Wed - Same with Back Fri - Same with IM, except the numbers represent the multiple of 100 I'll be sprinting. Following week, up the highest number I go. Anyway, I'm early on in the program, but already I'm doubtful if this will get the results. I based this whole idea on watching college and Olympic swimmers and figured, hey, they're training for sprint swimming, so that's what I'll strengthen. But I also know they dryland quite a bit. For me, that would essentially be weights. The thing that got me doubting the program above was looking at photos of Olympic swimmers through the ages. The guys in the 70s almost look rail thin compared to the guys today. The only thing separating them, I have to imagine, is what they did outside the pool, as swimming is, well, swimming :). So if you were in my shoes, what would you do to build up like one of these pro level swimmers - weights, or sprint swimming? I can do both, obviously, but I'd rather not waste precious time in the pool if it won't really advance what I'm after. Lastly, not to sound like a jerk here, but if you have a really solid opinion on this, please include a pic so I can see how your ideas worked for you. I'm fairly well along in my training and would want to rely on advice from someone who has really clearly and effectively implemented it. Thanks so much all!