meanewood: Thank you for your suggestion. That was my gut reaction when I discovered this. Treat it like a knot leave it prouder than the rest. But, the physics behind why this would break are a little more scary than the physics behind why a knot breaks. A knot is kind of like a hole through the limb you have to compensate for in thickness or width, but this even left stiff would still feel pull and push from either side of the shelf and them not being married could still spell Kaboom.
Thus, why I posted. Thank you for your input. I would jump at doing your suggestion except the stave is only 73" long so leaving a 3" stiff spot will put me in risky territory trying to get it back to 31". I was going to replicate the smallest bow on the MR I remember reading somewhere it was 73" long. (One wonders if it was only meant for the shorter arrows and thus more like a 28" draw) Have you dealt with this exact problem before with success? Your input is very appreciated.
Delcat: Thank you! Your video confirmed what I thought you meant. The downside of sawing I just thought of is the kerf created by the blade won't have quite as perfect of fit as from splitting, plus following the grain well since a saw can meander. But something as small as a scroll saw should leave such a tiny kerf as to be manageable. Were it happening in the last 12" or so I'd be more keen to try this, but so far down the limb I am fearful of screwing up the stave. I think I will nearly rough out the width dimensions of the stave while leaving full thickness alone and then reevaluate. Thanks again.
DC: So sorry. The total thickness is 40mm or about 1 5/8" it is also that wide and the stave is 73" long. The goal was to replicate the smallest bow on the MR b/c I remember somewhere saying it was 73" long. Alas, for months I have been trying to get my hands on the Weapons of Warre book with either a copy being available when I can't afford it or no copy being found when I can. Then, for Xmas my girlfriend surprised me with a receipt saying she bought it from Abe books. Very wonderful!... Well they've just notified us they lost it in the mail so are resending another copy. A bit frustrating. So, at the moment I do not know the exact dimensions of this bow. My 75" ntn 115# yew bow was 23mm 18" from nock so I might just make it with all sapwood left on. Yeah I even thought about scrapping the MR replica and making a more squashed profile longbow to get out of this. All of the above is on the table. I think once I get the dimensions of this bow I will rough out near to the width while leaving full thickness and then decide on how the shelf looks then and how to proceed. All input has been very appreciated and I will update on proceedings.