some NJS bikes are built for 110 spaced hubs (instead of 120), which also have narrower (9mm instead of 10? i'm not sure) axles.

that could be your problem. search for "110 spaced" for more info. you can coldset your frame to 120 and file your axles (or your trackends, but i'd rather file a replaceable axle than risk messing up on a frame) to accept standard hubs. but you should know what you're doing.