+1 on the extra nut if you can get one from HQ. And this would be the time to go adjustable if that's what you ultimately want. Brass is pretty malleable so if you have some skills, files, and sandpaper you may be able to tweak the fit yourself. (I don't know how the Orion nut is attached however.)
I had a set of nut files from StewMac but have since figured out that I could make more perfect fitting files from a block of wood and an old set of strings. I literally use an E string to cut the E-string slot. Results were pretty good, you just need to pay attention to the angle and try to get all the slot depths to match the radius of the first fret.
I should also say it helped to have the adjustable / removable nut because I was able to secure it to another chunk of wood while I operated on it. It would be difficult to do this if it was still mounted to the bass.
Jimmy J