Your question poses a small problem. No English coin was introduced in 1526 and no British coin was withdrawn in 1965.
Many English coins circulating in or around 1526, were still circulating in one form or another in 1965.
The "Testoon", later known as the "Shilling", was first minted in small quantities around 1489, but minted in much larger quantities from about 1544.
The Shilling continued to circulate along side the 5 New Pence and 5 Pence coins until 1990 when all coins were replace with a smaller 5 Pence coin.
The largest denomination British coin in circulation is the Five Pound (Crown) coin, although it is intended to be a commemorative coin and is not generally accepted as a "general circulation" coin.The largest denomination British coin in general circulation is the Two Pound coin.
None, it is made from a copper/nickel alloy. There has been no silver in any British general circulation coin since 1946.
Zero. There is no silver in any British general circulation 50 Pence coin, and there has been no silver in any British general circulation coin from 1947 onwards.
There was no 1977 British One Pound coin minted. The first general circulation One Pound coins was minted in 1983.
The British general circulation One Pound coin is made from a nickel and brass alloy. It is the brass that gives the coin the pale gold appearance. There are no precious metals in any general circulation British coins.
Five cents. It's an ordinary circulation coin
Such a coin does not exist. The last British Halfcrown coin minted for circulation was minted in 1967. The last British Halfcrown Proof coin was minted in 1970.
There is no silver content in any general circulation British coin from 1947 onwards. The 10 Pence coin is made from 75% copper and 25% nickel.
The highest denomination British coin currently in circulation is the Two Pound coin. Although the Royal Mint advises that Five Pound coin is considered to be legal tender, it was not intended for circulation and many businesses, especially banks, will not accept them.
Such a coin does not exist. The first British Florin was introduced into circulation in 1849.
You do not specify the denomination or the country of origin, but no 1966 British general circulation coin with the legend "Elizabeth II dei gratia regina fd" contained any silver.
The Royal Mint advises that 129,644,000 Sixpences were issued in 1965 making it easily the most issued, if not used coin, in 1965.