Except for a few of the Sydney minted gold coins, no 1910 British is classified as rare, although there are a few that might be a little expensive, due mostly to the fact that some of them are made from near pure gold or silver. You should be able to find a good range of 1910 British Coins at your local coin dealer.
With the possible exception of traders tokens (with the traders business name on them), there were no "Australian" coins minted prior to 1910. The only coins circulating in Australia prior to 1910 were British coins.
There are 0.48357 troy ounces of gold in the 1910 Half Eagle gold coin.
Scenes in British India - 1910 was released on: USA: 14 December 1910
REGINA is Latin for Queen. You will not find REGINA on a 1949 British coin because King eorge VI (REX) was the reigning monarch. You will find REGINA on British coins with Queen Victoria or Queen Elizabeth II on the obverse.
The Monarchs head.
Pictures of a specific coin are difficult to come by. Usually you should be able to find one on eBay, but the picture is withdrawn after the coin is sold. A 1921 British Penny would be near identical to all British Pennies minted from 1911 to 1922. See the link below for an almost identical 1920 Penny.
Assuming no mint marks and the coin is circulated, a 1910 Indian Head retails from $710.00-$900.00, depending on which of the 6 major grades the coin falls into.
The large bronze coin you describe is probably a British Penny from the period 1910 to 1936. The coin has no special significance other than it is a British coin and people used it to buy things. The "angel" on the reverse would the seated female warrior Britannia wearing a helmet, carrying a trident and shield, who is personifying Great Britain. Britannia has appeared on British Pennies for hundreds of years.
All British coins have FD on them . All British monarchs since Henry VIII have FD (Fidei Defensor, Defender of the Faith) behind their name on a coin.
The British Farthing was in use in Australia before Australia got its own coinage in 1910, but there has never been an Australian Farthing coin.
...There is no such coin as "Dei Gratia" which translates from Latin to "By The Grace of God". The coin you are referring to seems to be a British coin or one of Britain's dominions such as Canada because most of them have the words "Dei Gratia" or some abbreviation of it on the coin. If it is a British, Canadian or other British dominion coin, it will have a picture of Queen Victoria on the front. The reverse may or may not give the denomination depending on the coin, but with searching, you should be able to find the design that matches your coin and find out the denomination. Then repost a question including the country or origin and the denomination.
The British do not have a Twenty Dollar coin.