This is a tri-fold brochure dated 1978. The brochure was created by the General Development Corporation (GDC).
GDC was the largest residential land developer in Florida from the 1950s through the 1980s. Brochures like this one were produced and used all over the US and the world.
Development locations in the brochure: Port Malabar, Port St. Lucie, North Port, Port Charlotte and Port LaBelle.