Go ahead and modify the nut, nothing to lose.
I can make you a new nut PDQ as I have the tap I used for the one you've got. I can leave cutting the slit up to you if you want, though the cutter I have would probably go about that deep. You can measure the one I sent to see the max depth I can get, as it's easy to see where I stopped milling and went further with a bandsaw.
I can make you a new nut PDQ as I have the tap I used for the one you've got. I can leave cutting the slit up to you if you want, though the cutter I have would probably go about that deep. You can measure the one I sent to see the max depth I can get, as it's easy to see where I stopped milling and went further with a bandsaw.