I would love for someone like Jonathan Carr, Peter Lederman, or Steve Leung to explain how the cottage industry of cartridge manufacture can be done. I have to believe that the motor assembly is sourced from one manufacturer, the body from another or perhaps made custom by a machine shop, and simply combined and placed in a fancy box and voila. This is not like A.J. Van den Hul, also a cottage industry of sorts, building cartridges from scratch.
I am reminded of the Swiss watch industry in which 95% of the major labels use one of two stock mass-produced movements, customize them to varying degrees, and then design a fancy case and bezel around it. When Omega, after half a century of using ETA (third party stock movement) movements moved to in-house designed and built from the ground up movements, it shook the industry.