One of the "frets" is loose, drat. Wayne at GoldTone (the owner) advised me on the phone to re-seat the "fret" by carefully scraping out any dried glue that is in the gap, then putting a tiny amount of Elmer's wood glue on the bottom of the "fret" and before sticking it back in. I'm going to try that.
As for "fret sprout," he suggests taping off the areas around each fret and running a #220 sandpaper block (or pencil wrapped in #220 sandpaper) up and down perpendicular to the the length of the fingerboard for about 15 seconds per fret. I assume that's using fairly rapid strokes. I am not very good at this kind of thing, so I'm going to proceed with caution.