You do BEAUTIFUL work, thanks for sharing!
I've used MinWax wood hardener with some success, be careful with it though...
It does, on occasion, change the color of the wood a bit.
Usually use CA glue on smaller stuff.
Precautions include avoiding the irritating vapors, along with not gluing yer fingers together!
You can watch it smoke and hear it hissing and bubbling in the more rotten spots.
I've used it on buckeye burl pistol stocks in the past...
Long gone, they are, sorry no pics.