www.flying-models.com Plan CF132 $17 Oscar's 1/7 scale Widgeon full-size plan, includes construction article.
Nacelle plugs available free from Oscar, [email protected], but I would need a $100 returnable deposit.

www.rcairplane.net G&P Sales. Al Franklin's 1/4 Scale Widgeon. Fiberglass-foam short kit with full-size plans, about $1200. Includes fiberglass hull, nacelles (classic inverted Ranger or horizontally opposed), and tip floats, with foam cores for wing and tail feathers.

Background
Grumman wanted to offer a smaller, more affordable version of their highly successful Goose, and in 1940 they introduced the G-44 Widgeon.
The 5-place Widgeon had a forty ft. wingspan and was a typical rugged product of the Grumman "Iron Works", with a gross weight of 4525 lb. Flaps, retractable landing gear and fixed wing tip floats were standard equipment. Construction was all-metal, except for the flaps, control surfaces and aft outer wing panels, which were fabric covered.
About 275 Widgeons were produced, mostly for military service in WW II. They were used by the American
armed services and by several allied nations. The British called their G-44s "Goslings", an apt name considering their derivation from the larger Goose.
After the war, Widgeons saw service as executive, utility and bush planes throughout the world. Many were converted to use larger engines, both horizontally opposed and radial. Some "Super Widgeons", even had retractable wing tip floats like a PBY. About 100 Widgeons are still flying today.
Inverted Ranger 6-cylinder in line air-cooled engines, rated at 200 horsepower each, powered the classic Widgeon. The streamlined cowlings of these engines, similar to those of the PT-19, gave the fat, short-coupled little amphibian a pleasing, kind of cute, appearance, quite different from that of the other Grumman twins, which used big radial engines. Widgeons converted to horizontally opposed engines had a variety of nacelle shapes.