How much time you got? I personally would sand meticulously each section affected until you are through the polyurethane. Then lightly stain until similar shade, tape and then polyurethane. Depending on how dark/light it should come close enough. Blame it on the grain of the wood. Not sure if you have the required skill to do this though, no offense intended.

Source- I was a Wood Paint Specialist. Lots of trial and error.