The 3DK is a scan of a rehauled/rebuilt Sean Clark Small.
I posted this somewhere a while back, but I know how easy that stuff gets lost and forgotten in a huge forum.
The short version, if I’m remembering correctly, is that a guy found an old Myers mask he had in storage and sent it to Jimmy to be refurbished. The details on what it needed were kept pretty close to the vest. I don’t know what kind of condition it was in at this point and what Jimmy had to do to bring it back to life.
When Jimmy received the mask he realized that it was an original Sean Clark Small in pretty good condition overall. He asked the guy if he wanted to have it scanned and made into a wearable/sellable mask and the guy agreed. Bingo. The 3DK was born.
Edit: 3DK mask?