Well, the super-easy way would to simply scan it at a very high resolution, adjust it accordingly in PS and be done with it. Since this is done using "real" tools, there is no resolution limit otehr than the granular fibers in the paper structure making it eventually looking odd. If you still must redraw it, my first place to start would be Bristle brushes. A few very stiff strokes with a fan brush and low opacity would offer an relatively easy way to place those strokes. Multiple strokes stacked would then mimic the variations in density. And that means that of course you paint the blue stuff first contiguously, then the text on top...