Help: Replacement nut for original style Morse

I probably have messed up my nut. I’m getting some pinging on the g string when I aggressively bend. Looks like the slot is too wide, my fault if so as I’ve done some filing. I could try the trick of filling it with bone dust and super glue and refile. But if I want to get a new nut, does anyone know if this is a flat bottom or a curved bottom nut? Anyone know of a good replacement that is pretty close, understanding that some sanding is necesssary?