Upon removing the bolt, and giving it a slight twist, the remaining wood gave way and it separated cleanly. The inside had some kind of residue which may be a prior failed glue joint. Whatever it was, it gave way easily to 80 grit sandpaper.
I wet out each side of the tiller with neat epoxy, and then thickened up a batch with colloidal silica to the consistency ketchup, and then clamped it up to dry. In the morning, the glue had set up, and the joint appeared solid as new.
The next step took the longest. I attacked the failed varnish with an 80 grit sanding disc on my orbital sander. Even though it's a failed layer, it hung on for dear life. After almost an hour of carefully sanding through the profile of the tiller, it came out fantastic. The tone of the wood evened out, and the split is barely visible.
The next problem turned out to to be the tiller extension, or "hiking stick". It had been wrapped with an amazing amount of duct tape which was no small feat to remove.
|Lots of duct tape...|