Let the skins change with the arena, and snapshot events or FSO always require the squad to fly with the same skin. Then the skins don't necessarily have to be on the server hogging space until a special event.
I also think that squads should be able to create a skin that does not have to be historically accurate, that can reflect the squads interest (even if it's only used for FSO). Who knows, there may even be some money involved for you veteran skinners (hint hint).