Mike, a great build and impressive sideboard! I appreciate your extensive display of hand tool use - this is what the Neanderthal forum is all about for me. I frequently have trouble trimming the width of tenons to get the 3rd or 4th shoulders. I use a pencil and ruler to make a line to rip with my handsaw, but I am not satisfied with my results. Your Veritas sliding square/ruler looks to be the answer. It seems you highly recommend it? Thanks Mark