Thank you kindly fellas!  It is indeed all heartwood.  I chased a ring on a belly split.  A lot of you that have never used walnut may be wondering if it really needs to be as overbuilt as this bow is?  No...it does not.  Momma just likes a really long bow.  To get the best out of it, I had to adjust the tiller a bit.  It shoots nice enough with the adjustment, that I'm considering making myself one of similar specs for 3d shoots.  Thanks for looking!   Josh