Find one that doesn't have a patent and reverse engineer it.
I imagine the first/original control system was extremely difficult to develop. But since the technology already exists you can reverse engineer it.
After that, you pay a supplier to make parts. In my experience, these suppliers will end up redesigning to match better with their process, but still meets critical specifications.
I'd post my contact info, but I believe I'm targeted by an HN mod.
At this point, it would be better to start looking at expired (and about-to-expire) patents. A circa Y2k printer would be a perfectly acceptable design, IMO.
Glancing back through your posts, I see pretty clear reasons why people would have downvoted your gray ones.