the NT is its own design just as every other marker is, there is no need to say one design looks like another, all spool valve markers share similarities, same with stacked tube poppets.
also people think this is similar to thorps design, from what I can tell it MAY have started with his but the internals in the NT are quite far from what he showed everyone back in the day. 3 years of R & D at Dye are probably the culprit.
ABET Accredited Level II Machinist - CNC programmer - Mech. Engineering Technologist
Rio Grande Inc.