Was just listening to an interview with Peter Beck. He clarifies the US-NZ question. Short answer is it is both, I had my proportions off with being more (3/4) American now. It's been American company since 2012. The US factory is 3 times larger than the NZ factory and makes stuff we're can't do here.
https://podcast.radionz.co.nz/mnr/mnr-20181112-0826-rocket_l...