In that picture Bradley Cooper looks like a young, lighter version of Richard Lewis. I can't see any resemblance to LB at all. Sorry.
I like Patrick Dempsey but, eh, I don't see it.
Maybe it's because none of these guys- except for that "Twilight" actor- have a youthful appearance, and quite frankly LB had a baby face for such a long time in the 70s/80s...he needs a young guy with beautiful eyes to play him. And be able to carry the fro look with confidence.