I don't have any problems with the way the original is built, regarding the alignment of the patchbox in the buttstock. It just screams Peter Berry - it's practically unique. If you decide to tip the box up so that it doesn't interfere with the lower butt molding, the angle of the box relative to the buttplate will also be changed. I think that Berry was concerned more about the patchbox coming off the butt plate at close to ninety degrees, than the box interfering with the molding. To my eye, if this is altered to accommodate some contemporary notion of how a 18th C rifle should be built, you'd be missing the point. What is it about the original that captures your interest?