Not sure if it's more valuable. There are a LOT of "foreign" SOHC4 bikes that were imported back to Japan... wonder if they get a higher price than "Domestic"?
The Japan models will have specific lighting, a headlight designed for left side of the road driving in particular. Maybe they have the "parking light" in the headlight that US models did not have (because those headlights were not DOT approved). They would have had the speed sensor light, indicating "too fast!"... all Japan vehicles capable of going above legal highway speed had to have a speed warning system, maybe still do.