You could have a go at bleaching the wood with hydrogen peroxide to make the pieces a more even and lighter colour. It's been done once before here and worked very well IMO. No idea of the process so you''l have to search for that. But if you can glue up the crack well, without a big join line, then it's worth a go. And if it doesn't look any good then there's still the solid colour option, but before that, a mix of stain with a matching tinted nitro lacquer on top does a pretty good job of blending mismatched woods together if you use a darker colour and several tinted coats.