when i did my nick mod, the old sheath i had made when it was still a santaku still fit, and even now my sj nick mod still fits in it, though a bit wobbly.
if it is a clip pointed no-e, it should fit into the kydex... if it was built all on its own, and not a no-e blank to begin with, it may be a little tight or loose... kydex is weird when it comes to fitting other knives into the same sheath even though it should work...
edit - if its one of the kydex sleeve in cordura sheaths you should have no problems, as long as its the same thickness. im currently using a 3/16" sj kydex/cordura to house a 1/4" sj (both saber ground) and it does alright. not perfect, but it works without any major rattles.