I'd be rather worried by the knot in the pic below and the dark line going out left from it.
I would get an old needle file (or some such) ground to a tiny chisel point and clean out around the edge of the knot (and that line), you may find that once you have cleaned out the crud there's no good sound timber.
Don't panic! You can excavate the whole lot, fill with a plug, then take it down to a flat concave face and overlay a long sliver of sapwood which will give the back some continuity (it also eggectively moves the manky stuff in towards the neutral plane of the bow where it won't be under such strain.
A nivce looooong patch can be blended in to almost invisible.
I've done it on a few bows and it's better to be safe than sorry.
I can see you've followed the dips and swoops, but there's that area with pins where the sap is pretty much transparent too, that may be worth a sap wood patch.
This link shows a V similar repair I did on an ELB.
http://bowyersdiary.blogspot.co.uk/2011/05/repair.htmlDel