Interesting and a very good finish.
But you've not said what you did to affect the 'repair'. Looking at it It does not look like epoxy & coffee grounds, or even just epoxy on it's own. I can see what I think is a Glue trace on one of the pictures looking into the bowl, so I'm sure you've used it somewhere.
I have to admit, I've never turned Black Walnut as a bowl, small stands and beckets as faceplate work, 5" and 4" respectivly, mostly I spindle turn it.