that grain effect is super easy to accomplish - when fillling the grain on an Ash body, simply use a dark tinted grain filler (the grain filler darkened for Walnut is perfect for this)
once the body is finish sanded are prepped to paint, all of that dark filler is isolated in the wood pores leaving all of the high areas the natural light color normally seen
there are several different shades of pore filler ranging from super light (what is traditionally used on Ash) all the way to black. if you finish yourself, you can always tint the filler to coordinate with your planned finish (say a really dark navy blue for a transparent blue finish)
you do need to be careful with handling the body during construction, since any scratch line or sanding scuff will get filled with the dark colored filler and --really-- stand out
and spending $500 for the bass, keeping the control plate, and then flipping the bass is a pretty good deal. $500 is about what I had to spend to get my first small batch of 10 lefty control plates produced for my Heritage Series basses
all the best,
R
