A crown, crossed rifles and a "V", I'd be looking for an infantry HQ unit with either a "5" or "15" in its designation. At least thats what you would get from Roman numerals.
The other option would be a Victorian unit, but again infantry
and HQ.
Found it: 5th/6th Battalion Royal Victoria Regiment
http://en.wikipedia.org/wiki/5th/6th_Battalion,_Royal_Victoria_Regiment
Its a current unit with a history going back to colonial days. It has a significant battle history, particularly in WWI, Galipoli landings, France, WWII in the Western desert, Bardia, Tobruk and El Alamein plus the Pacific.
It would be a unit sign to wear with honour.
(
Sorry Mick I missed your comment after the dog face bit. At least its confirmation of the sign.)