No, but since we’re talking guns made prior to WWII I have to say that most 99s I’ve seen post date that event. I also have to say that most of the walnut stocks I’ve seen did not have cracks behind the tang and of the prewar guns many of the cracks I’ve seen were in the more slender schnable forearms. Having said that, I’m not sure walnut is the best stock wood as other woods seem to be stonger and lighter in weight, they just don’t catch our eye like walnut does.
