The value of any coin would depend on the year and condition of the coin. At the very least, a 22 carat gold sovereign would be worth its weight in the current bullion value of gold.
The were approximately 2,718,000 British 1838 gold Sovereigns minted.
Some Henry VII Sovereigns do still exist, but you would need to sell your house to buy one.
There were 14,000 1973 Isle of Man gold "uncirculated" Half-Sovereigns minted. There were 1,250 1973 Isle of Man "Proof" gold Half-Sovereigns minted.
The plural noun sovereigns refers to kings and queens, monarchs, rulers. It was also used colloquially for gold coins with a value of one pound, and for current bullion coins.
Without more information, it's hard to say. Most sovereigns trade for gold value, plus a small premium. Sovereigns have a little less than 1/4 ounce. Divide current gold prices per ounce by four, add ten or twenty bucks. That would be close.
Modified coins have no collector value, any value would be associated with the necklace as a piece of jewellery, or the melt value of the gold in the coins. Sovereigns contain 7.3224 grams (or 0.2354 troy ounces) of gold (22.05 mm in diameter). Half-Sovereigns contain 3.7 grams (or 0.1177 troy ounces) of gold (19.3 mm in diameter). The coins will be worth whatever the current bullion value of gold is. At this moment (28-Sep-2011), the bullion value of gold is $1,656.42 USD per ounce.
3.89 Sovereigns in one Troy ounce
Sovereigns are made from 91.67% gold and are not plated. There were no Sovereigns minted in 1953. Queen Elizabeths Coronation commemorative coin was the 1953 Crown which is made from a cupro-nickel alloy. Modified coins have no collector value.
All British Sovereigns issued since 1817 are made from 22 carat gold. At the very least, any Sovereign is worth bullion value. Any collector value would depend on the year and design of the coin, the condition, and even where it was minted.
I have a Dennison Watch Case Co. 14ct Gold Sovereign Case # 23748 with Two Gold Sovereigns from 1897 and 1909 in it. Markhall5@verizon.net
The face value of a Sovereign is One Pound GBP. Since Sovereigns are made from 22 carat, or 91.67% gold, and taking their collector value into account, their actual value could be anything.
Sovereigns were not in circulation in 1692.