Life happens
But yeah, a radius sanding block for the win, and plenty of sandpaper, don't start too fine, I think I use 60 or 80 grit. And in ebony, it is a mess, fine black dust everywhere. Don't suppose a router will be much better.
If you can sharpen, and you have a proper handplane, use that, not the 110 I saw in the pictures earlier, but a number 4 or 5, with the mouth tuned to a small opening, and a razor sharp blade not set too deep. Not sure how it'll cope with the inlay though. As they say on the Musical Instruments Makers Forum, "test it on scrap first!".