RE: Japanese F3A planes
A lot of the gorgeous planes you are looking at are either one offs, hand built from kits, or both. Even if they decided to export the kits, there is a rapidly declining base of people that could build them even if they had the kit. The number of hours that goes into a model like those is way up there and most people don't want to take that kind of time to 'make' a pattern plane.
Woodie