An Antique Steel Curb Bit - Bit271

A steel curb bit with a shaped mouthpiece that can revolve.
It has wide shaped cheekpieces with two rein slots in each, these also turn.
It is similar to a IX Lancers bit and I suspect it is a military bit and possibly American, but I can find no marks or stamps on it

Mouthpiece 11.5cm (4½")
Cheeks 18.5cm (7¼")
Weight : 474g (1lb ¾oz)