I think this is possibly a 14HP Crossley radiator cap.The Dia. is 1-7/8". It has a 20TPI thread.The bakelite part is excellent, the base has a nick to one edge, but it should still screw onto a radiator.I can post this and I accept PayPal.
Left chromed indicator light LABINAL 2422 Citroën 2CV from 1959 to 04/1963 + 2 right Labinal housing1 complete this is the left one. The other two are right indicators. These are chromed, only housing.The items are in really good shape.