I don't really think there's a quick-and-easy solution, though I could be mistaken. For that sort of thing, a lot of it comes down to finding a nice source for a particular bunch of lines. It's generally pretty tedious, but cloning small sections, maybe switching layers for those that are close to each other, and erasing excess from the clone, you can usually do a decent enough job. The dodge tool also comes in handy here or there if you need to emulate a fade.