DonJoe, they look really nice. You and your sons should be proud. I think there's a takeaway for them about patience here. It didn't sink in for me a good chunk of my life. Slow and steady perseverance will often yield a wonderful result. In a fast paced world where things can't come fast enough, finishing wood like this can be really rewarding. Smelling the roses and all that. Well done.
Naboo, walnut comes to life with a hint of orange in the finish.I suspect Tung oil would have a pleasing result as would most oil-based finishes. They almost all impart a slight amber hue. Penetrating finishes will tend to leave that "woody" look that many like.
You mention bubbles, are there bubbles in the veneer? If so, that would be something of a problem that could perhaps be fixed. How did you apply veneer? Paper backed or raw? Many here to help, but perhaps best to start another thread.