Earon told me that he had a brief relationship with NW and when the relationship ended she took one of his comps and ripped it off. But I think there is more to it than that.
Earon mentioned that he worked with Jay Wilson of Tri Jay machining on various projects including the Tri Car (Tri J and Carter=Tri Car) and I imagine machining some of his original comp parts.
Nicky Wilson was a relative of Jay Wilson and had Tri Jay make her NW comps.
Seems possible that Tri Jay was making some of the parts for both pumps at the same time to produce a larger run and bring costs down for both parties?
Early comps used the low profile sight rail (same as NW) and later comps used tricar style sight rail.
Some have flat edges on the front and back of the pump handle.
Steel sight pin at front of barrel, some used a fluorescent dot.
Some used bolt through center of frame, most used glued on grips. Most have the hole for the bolt in the center of the grip frame regardless of whether they used it.
All used low profile sight.
All used round pump handles
Brass front sight pins
Serial number on base of grip frame
Besides the external variations (pump handle, screw through grip, sight rail, lead sight pin vs brass) there are also internal differences which are present, although Earon likely changed parts constantly so this also might not be a sure sign one way or another. I think NW was a little more consistent with parts.
Anti Kink Full bolt with allen or 4 hole adjuster.
Three port powertube, possibly a short tube.
Bolt/Hammer combo isn't compatible with NW internals (smaller anti kink?).
Anti Kink bolt with edge shaved off in feedport.
Early internals were parkerized, later were nickel plated
Bolt/Hammer combo isn't compatible with Carter internals (larger anti kink?).
Long powertube with 2x base holes angled up not straight through.
Post some pictures of your internals and some better pictures of your paintgun if you can.
Hope that helps and if anyone has any more information please post.