Doubtful actual prints for the brand name Sunfish are available. That would be like getting ahold of the actual prints for a Honda Accord.
My local library has or had - it's been awhile since I was there - an old fiberglass instruction book called ( Boatbuilding and Repairing with Fiberglass by Melvin Willis ) One of the book's projects is a Sunfish type sailboat.
The Moonfish kit is available off the internet. I see it referred to at the Wooden Boat Forum about once a month. Just Google Moonfish.
Lots of kit boat and nail & glue boat plans out there for Sailfish type boats. Some new and some older than the brand name Sailfish itself. They use to fill the back pages of magazines like Popular Mechanix and Boys Life.
The brand name Sunfish and Sailfish once came as kits, but as I understand it everything came pre-fab. The directions only show how to assemle the pieces so no patterns to make the segments from.
There was a little hubbub recently at Wood Boat Forum about the discovery of a set of the original Sunfish assembly directions. You can check out who's got them and if they are willing to make you a copy ( http://www.woodenboatvb.com/vbulletin/upload )
Visit the Yahoo Sunfish Sailor site. Look under the files section for "Classic Wood Fish". There has been a recent file set added from a 1960 sailfish. Blueprints, assembly instructions, and material lists are available in very clear, readable PDF file formats. It does precede the Sunfish, no cockpit, but what a great project to work on.