You can read the instructions for the Model Shipways kit, complete with illustrations, on the web: http://www.modelexpo-online.com/images/docs/MS2015/MS2015-Fair_American-Instruction_Manual-Complete.pdf .
You can also buy the plans, but they aren't exactly cheap: $50.00.
It's to be remembered that the old Pyro kit is, as GM pointed out, a pirated, miniaturized version of an earlier, solid-hull version of the Model Shipways kit, which is, in turn, a model of a model. The whole sequence goes back to a contemporary (or near-contemporary) model of a brig in the U.S. Naval Academy Museum. That model has the name "Fair American" painted on the transom; that's the only reason to attribute the name to an actual vessel. (The name was quite a common one in the late eighteenth and early nineteenth centuries.) Quite a few people have done research on that model over the years, but nobody has ever figured out exactly what vessel it represents or when it was built. As the instruction book indicates, the rigging contains some anachronisms (the dolphin striker, for instance) that don't click with the guesstimated time period of the American Revolution - but there's no way to tell how many times the model has been restored or altered. We don't even know on what plan, if any, it was based. Even the scale of the old relic is a guess.
I'd have to compare the Pyro kit with the MS plans to be sure, but I'm inclined to agree with Mr. Helfrich: it does look like Pyro may have exaggerated the beam a little. It also looks to me like the quarterdeck may not have enough taper to it; the MS kit's seems to be proportionally narrower at the transom. I don't think the people responsible for designing those tiny sailing ship kits were particularly interested in making them look like real ships. (The Golden Hind, which I can remember building with great pleasure when I was in elementary school, has a hull form that's pretty amusing.) I remember thinking of them as 50-cent kits that could be picked up at the drug store around the corner from our house. (For a dollar you could pick up the kit, a couple of bottles of Testor's glossy paint, a camel hair brush, and a tube of glue, and have enough left over for a cherry phosphate at the soda fountain. I remember painting that Golden Hind overall with Testor's gold. My parents thought it was beautiful - or, as my mother probably put it, "adorable.")
GM is right about the locations of the yards: the person who drew the instructions told the modeler to mount them one "level" too low. The lower yards belong just a few scale feet below the tops. I can't blame Mr. Helfrich if he leaves them as they are, though.
The idea of "re-scaling" the spar plan is interesting. I can't see any rational reason to use the kit masts and yards at all, though. An hour's work with some small dowels (or pieces of wire), and maybe some plastic sheet for the tops, would produce something considerably more realistic than Pyro's nondescript shapes.
At any rate, it does have the potential to be turned into a nice little scale model - and given the history of the plans, nobody can really say how accurate it is.