Don't know who makes them, but they clearly are a custom-made proposition as the market for primer making machines is about zero.
If what I read in Ammunition Making by Frost is still true, the machines work on large plates with precisely located holes (like steel pegboard) to punch out hundreds of primer cups at once. Primer composition is hand spread into matching plates and the resulting pellets are then pressed into the cups. Subsequent steps are foil application, lacquering and anvil placement. It's mostly the handwork of making the pellets that sets the production cycle.
Frost was heavily influenced by plate technology which was and is quite labor intensive...that's true. 20 years later labor is cost preventative and the safety factor is of much greater concern. I believe there is a much greater demand for a primer machine than is thought...there are lots of third-world militaries that would benefit from a government plant using such a machine...I just thought someone here might know where they come from. I guess China...