I have a write-up here, on the Operation-DITTO GitHub organization. It will expand when revisions are deemed mature enough to contain part listings, but technically you can build the prototypes yourself any time. You will also notice the software involved, along with more images and the CADs. Everything in this organization is open-licensed.
Creds to @z2442, who this project was developed alongside. He was responsible for most of the CADing and some of the serial controller code.
Full credits are available on the write-up, including sources to information.
Here are some random images, taken from the "press-kit" that is also on GitHub.