Most round British silver Threepences issued from about 1717 to 1926 inclusive would have a Crowned "3" enclosed by wreaths.
All British silver Maundy Threepences issued from about 1817 to present day would have the same or very similar design.
Winston Churchill featured on the reverse of the 1965 British Crown, commemorating his death.
The design on the reverse of the Half New Penny coin was a crown.
There was no 1970 British Crown (Five Shilling) coin minted. The last British predecimal Crown (Five Shilling) coin to be minted was in 1965.
There was no British 1886 Crown (Five Shillings) coin minted.
There was no British 1846 Crown (Five Shillings) coin issued.
The 1826 British Shilling and Sixpence coins are both sterling silver and both have a lion standing on a crown on the reverse. The Shilling is 23.5 mm in diameter. The Sixpence is 19 mm in diameter.
The only 1967 British coin with a sailing ship on the reverse is the bronze Halfpenny. In mint uncirculated condition, it might get up to £0.50 GBP.
There were no 1740 British Crown coins minted. The Crown coin was not regularly minted during the reign of King George II.
Your coin is either a British George II gold Guinea or a Half-Guinea. The Guinea coin is 25-26 mm in diameter, the Half-Guinea a little smaller. Either coin in any condition would be worth something, if only for the value of the gold.
A silver pattern crown coin is a British coin that was produced between 1707 and 1965. This coin is made of silver and has a profile picture of Queen Victoria on it.
The Two Shilling (or Florin) coin is a British coin. British coins do not have the country name on them. The Two Shilling (or Florin) coin was also issued by a large number of British Empire/Commonwealth countries, but will have the country name on them somewhere.
The British 1889 Crown does not signify anything, it is a "coin of the realm", legal tender in the United Kingdom. The British predecimal Crown was worth 5 Shillings. The obverse shows the Jubilee bust of Queen Victoria with the abbreviated Latin inscription "VICTORIA D:G: BRITT:REG:F:D:" meaning, Victoria, by the Grace of God, British Queen, Defender of the Faith. This inscription and variations of it, appear on all British coins and many coins of the British Empire/Commonwealth countries and changes accordingly when the king or queen changes and the state of the Empire/Commonwealth changes. The reverse shows a mounted St. George slaying a dragon. The design was by Benedetto Pistrucci and with minor variations, has appeared on Quintuple Sovereigns, Double Sovereigns, Sovereigns, Half-Sovereigns and Crowns since 1817.