Id leave both sides of the cut a little over sized and creep up to the fit you want. I think most of the time might be spent jigging up reliable holding fixtures. Maybe, use your best strategies to minimize tear out since the butt Id figure is near finished dimensions. I think it would only be luck if you got two perfect cuts. I also think the joint would glare a little even if well done, maybe you can move it to well inside the checkering panels, as it appears expanding the checkering wouldnt look quite right based on your drawing. Best of luck with it.
