Apple Iphone 3g 8gb on o2 ?

Apple Iphone 3g 8gb, Works on O2 unsure about others, Works ok though is being sold as spares because it needs a new mute switch,switch is there and works but silver piece has snapped off. It has a 16g white back casing which has a couple of cracks and could do with replacing,will come with box and usb lead,no charger part,has been restored through itunes to factory setting. Screen has scraches as can be expected from a used phone. Collection only would swap for a decent radio control helicopter or a electric guitar text me or call..