The neck of this instrument suffered a severe trauma. It was snapped off at a right angle. As a result the edges of of the top where the mortise flares out were snapped off with it. Luckily the neck and ribs were, for the most part, spared. After resetting the neck I cleaned out the gap to fit a new bit of edge to both sides. Here is the cleaned up gap.
And the dry fitted edge. I will scrape to get the final fit.