"Mustache Pete" was a derogatory term used by the younger mobsters when referring to the older generation in general. The older ones didn´t necessarily wore mustaches.
No photo of him has been publicized exept of the few snapshots taken on his dead corpse. And none of them show his face properly. Hollywood would not have known how he looked like.
You can find the photos of his dead corpse in the "Rare photos" thread in here.