I haven't used veneer, but I once saw a stock that had been badly battered and heavily sanded that the gunsmith (a guy named Brian Burgin, now retired, who built a small frame custom Martini .22 for me) had wrapped a layer of veneer around the entire stock to bring it up to the correct size and hide the many flaws. It was spectacular and the seam, which ran along the bottom, was almost invisible. With a bit of grain painting at the joint, I'd venture a guess that you could make that addition completely invisible.