Nice save!
Very neat workmanship, you have great skills. I had to enlarge the pics and look very closely to see what you had done.
What I see is are closely fitting patches with very tight joint lines, that along with careful selection of wood with matching wood grain and direction makes the repairs all but invisible.
The OP's butt stock could be patched. Nothing to lose if it doesnt turn out. Walnut makes great kindling.