Gas cap rebuild
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
Civilian flip-top gas cap (common later style)
These detailed photos should be enough to help you disassemble and reassemble the late style, flip-top gas cap.
These photos represent the original appearance before chrome and zinc plating brightened everything up.