Strictly speaking,
Swallow and
Amazon were both real boats, but used in works of fiction. (
Swallow kept her original name, while
Amazon was, in the prototype, a dinghy named
Mavis.)
The boats featured on Stu Wier's site The Boats of Swallows and Amazons do not pretend to be either of these vessels, but they are either of similar design, or built with similar intent.
Stu Wiers site, was until today hosted by AUSTars, the Australian branch of The Arthur Ransome Society. But it has now been transferred to the site
All Things Ransome -- follow the links.
It's now had three different hosts as far as I know, and I believe that a link to an earlier location existed on The Mother of All Maritime Links, which was indeed created by John Kohnen.
I hope this clears things up a bit.
Mike