Have run into a bit of a back and forth in terms of getting my transport sorted.
These parts are so close as to not actually work as designed. This brass nut was sent as a replacement for a mis-picked Delrin plastic nut (originally shipped in the larger size of the other screws). I'd like to employ the clearly higher quality metal part, but need to make them work together.
My hopes are that the out of whack thread starting at the point it is turned down are what is prohibiting me from threading the nut. I'll file those bent ridges down without side loading and hope that allows freedom of movement.
It's either that or tapping out the nut.