I think mostly copper.
Such a coin does not exist. George V did not become king until 1910.
King George (Georgivs is a latinized version of the name)
King George V wasn't on any coins until 1911.
The words Georgivs II Rex on a coin (or similar) would translate as George the 2nd King, or King George the 2nd if you prefer.
George III, the King of England from 1760-1820.
Part of the Latin title of King George V, commonly used on coins. GEORGIVS V DEI GRATIA REX ET IND IMP means, GEORGE V BY THE GRACE OF GOD KING AND EMPEROR OF INDIA.
The British penny that you refer to has a portrait of King George the Sixth on the front and a picture of Britannia (which is meant to be a personification of Great Britain, much like "Uncle Sam" is a personification of the United States) on the back. By the way, the phrase "GEORGIVS VI D:G:BR:OMN:REX F:D:IND:IMP." is abbreviated Latin for "George the Sixth, By the Grace of God, King of All Britons [or "Britain"], Defender of the Faith, and Emperor of India."
A coin marked with "GEORGIUS" or "GEORGIVS" could be any British, British Colonial or British Empire/Commonwealth coin issued during the respective reigns of any of the six King Georges. George (I)(1714-1727) George II (1727-1760) George III (1760-1820) George IV (1820-1830) George V (1910-1936) George VI (1936-1952)
King George IV did not take the throne until 1820 and there was no 1773 British Penny minted.
King George V
King George V
King Edward VII was king in 1908, there are no King George 1908 Pennies.