Hi Rolls
Gilman Zhang is the contact at North Group. His email is
gilman@northgroup.cn
In a recent email, Gilman told me that North Group triplets and Jinghua Optical Co. triplets are all made by Kunming Optics Factory.
He has been a bit unreliable answering emails lately, but China recently had their big annual holidays, so maybe he has some catching-up to do.