I'd say Moustache. No such thing as a Derbyan Swagger... >.>
From the eyes and shape of the head, it looks a lot more like a Moustache than a Derbyan. Correct me if I'm wrong, but, don't Derbyan Parakeets have a similar build/facial look-structure to an Indian Ringneck? Moustache Parakeets seem to have a some typical parrot-face structure. (Large Conure for example)