I remember taking road trips with dad to see the differences in between the CCSB 12's and the Eddy & Duff Doughdish. The CCSB boats used the Cape Cod Bullseye hull mold, and therefore have the curved transom and higher cockpit sole for the "self-bailing" cockpit. They also weigh in at 1375 pounds.
The Eddy & Duff Doughdish was built from a plug made from a wooden 12. It has a stiffer, thicker hull made of airex sandwich core fibreglass. The Doughdish weight is supposed to match a "wet" wooden 12 at mid-season, and weighs in at 1500 pounds.
The Doughdish is class accepted by the H-12 class association, while the CCSB 12 is not. Now of course you could say that Bill Harding is also the class association president, and you'd be right. But the hulls aren't the same between the two either.
Other comparisons:
The CCSB boats were trimmed in mahogany. The E&D boats in teak. (I like mahogany better) The CCSB boats had nicer hardware. But today there's good hardware to be had. There wasn't in 1981! The E&D boats have the proper shaped molded shear-strake rail. This is a major factor to me, along with the varnished teak on the inside of the transom.
Jon

Adam: that boat on Lake Champlain would be perfect if it didn't have a centerboard. If I wanted one, I'd buy a Long Island Class sailboat: 16' by 5' by 8.5 tons...