As far as I know if you're selling things in kit form you're excused from any/all regulations and liability. The kit airplane industry in the US was a reaction

As far as I know if you're selling things in kit form you're excused from any/all regulations and liability. The kit airplane industry in the US was a reaction to strict liability laws that made private aircraft manufacture and ownership prohibitively expensive. (My old man has built and sold a few.) I would guess if you can sell / operate an experimental aircraft without restriction you could do the same with cutting tools.