I searched around a bit (I'm sure you've already done this) and the best I could find was an
unsatisfying and incomplete drawing of the Mk3(?) on
this site. I put a question mark (?) after Mk3 because the drawing doesn't even have the version number on it, it just says "The Nozzle". If that's a reference to the scene from the Venture Brothers then I guess it is kind of funny, but it doesn't really help anyone wanting to build one...
I poked around a bit on
Prusa's github but I couldn't find any solid models of the hot ends there. Maybe they're in there, maybe not.
There are some pictures of a Mk2 in
this post in the German forum. Maybe those might be of use.
For a design that is so touted as being "open source", the source doesn't exactly seem very... open.