6" (4" minus the gaine) x 2 1/4" dug fuze marked around the widest part of the base; LA 75m/m P.R 1929 VAD. Assuming VAD is Vickers Armstrong Dartford, but the 75 m/m and the threading aren't commonwealth characteristics (that I'm famliar with) so.... Vickers commercial/contract? Assuming 1929 is the date, it is a very aerodynamic fuze for the age and not likely AA as PD HE. Thusly, WTF?