I have been trying to identify a similar boat (I'll post my own entry later with pictures). The previous owner claimed it's a Cottontail sloop, and there is sooo little info on the boat. I did find this one resource which is an older book copy listing of couple hundred types of older boats. The link below is link to online resource showing the scanned copy of the book with original photos! It is the only place I have found online with a photo of this phantom boat. Published year 1963. Enjoy, and feel free to pass this along!
The sailboat classes of North America; - Biodiversity Heritage Library
The sailboat classes of North America; - Biodiversity Heritage Library