The boat in question, the one for sale in the opening post, and billed as a Nauset 25 does appear very much like what Nauset called its 24. I could be wrong, but look at the bow of the boat for sale, the subject of this thread, and the bow you see in the thumbnail photo at the bottom-left of the Nauset 24 advertising sheet below. It looks like the same sassy-looking clipper-raked bow.
However, Nauset described its "249" as having a 10-foot beam, and this sheet below says 9'6".
Maybe there was some "rounding up" going on with the beam measurements, or maybe it had something to do with the rub-rail extension that Nauset people have said turned Nauset's 24 into the "249" model (the extension giving it a LOA of 24' 9").
A rub-rail that extends LOA would augment beam, as well, wouldn't it?
The advertising already calls the 24 at 9'6" beam "SUPER WIDE".
Still just trying to sort this out.
As for the background of the Nauset 24, it has been described as said above: originally was the Florida-based Morgan 24 (designer unknown), an outboard, that when the molds went to Nauset were given a keel and turned into an inboard. At one point the keel was narrowed by Nauset to improve stability at speed.
View attachment nauset.24.photo.sheet..jpg