This ones a bit tough. Brian ("Finler") sent me a whole zip file of photo's - I'll post some later. I'm certainly not an expert on Herreshoff construction - I'll have to default to yourself, Jon or others here - but there are a number of similarities. Certainly the hull appears to be one of the 21 footers...This is what I know...
In B&P"s book they call the class the "21 footer class" (interesting that the NYT article calls it the under 22 footers). It appears to be based on a very broad rating rule (was this still the Seawanhaka rule?) as centerboard boats as well as full keel boats competed in the same class - In fact Rogues two sister ships built at the same time -Onagh and Radiant - Radiant was a centerboarder and two feet broader.
It also appears that the first in the class was the well known "Cock Robin" #460 (1895). It is also apparent that many of the 21 foot LWL boats in the registry are also in the class although the registry does not list them as such - See "Hazard", "Cockatoo", and "Jilt" as examples.
Now for the clues in the Brian's Pictures - The hull is in need of a major resto, and much has been stripped off.....But....
Certainly the hull shape and dimensions conform to the rule - so I'd say yep she'd definitely a 21 Foot class. If Brian is correct on the 7' 6" beam - there is only one I can find - that would be Cock Robin.
Now the not so sure part - she appears as a raised flush deck boat with the cabin extending right to the gunnels - something I wouldn't expect from this time frame (IE the 1890's through the very early 1900's). I know HMCo. did build flush decks - see the cruiser Ventura #867 - but thought this was a 1920's/30's vogue type thing - but of course I could be wrong - and of course a lot can happen to a deck/house configuration in 103 years.
Hardware - now this can be replaced of course, and much is already missing, so nothing is definitive - but there are pics of cleats (not Herreshoff - appear old chromed - like like those Bronze Rostand type), blocks both Wood and bronze open frame type - non herreshoff, and the traveler (don't think is Herreshoff either). The winches could be...The rigging is doubtful to be original.
If I was a betting man Id say A 21 footer class, but not Herreshoff built/designed....Again I reserve the right to be wrong

Let me know what you think - I'll post a few pics - and send the Zip file....