With broodstock like that, I think it's a matter of getting things back into a ratio of your goals ( big LMB). You need more BG in the right size to feed the larger LMB. I bet all the BG fry are getting eaten by the smaller bass before they have a chance to get bigger and that will feed your soon to be trophy fish. Add cover like snrub says to improve their chance. Target Feed the BG to get them to grow faster. Improve, if you can, more breeding areas for the BG to spawn. Yank out as many of the smaller size LMB until you start seeing a better diversity of sizes of BG. Possibly add another type of forage fish like Bill D mentions.
