These coins are still potentially in circulation so, unless they are part of a Proof or Uncirculated mint set or are individual Proof or Uncirculated coins and in absolute mint condition, they are worth Two Pounds.
A British 2004 Two Pound coin (QE II)(Trevithick's Locomotive Penydarren), uncirculated and in absolute mint condition could fetch up to £4 GBP.
A British 2004 Two Pound coin (QE II)(Trevithick's Locomotive Penydarren)(specimen in presentation folder), uncirculated and in absolute mint condition could fetch up to £7 GBP.
A British 2004 Two Pound coin (QE II)(Trevithick's Locomotive Penydarren)(brilliant uncirculated in in silver), uncirculated and in absolute mint condition could fetch up to £20 GBP.
A British 2004 Two Pound coin (QE II)(Trevithick's Locomotive Penydarren)(Proof FDC), uncirculated and in absolute mint condition could fetch up to £8 GBP.
A British 2004 Two Pound coin (QE II)(Trevithick's Locomotive Penydarren)(Proof in silver FDC), uncirculated and in absolute mint condition could fetch up to £35 GBP.
A British 2004 Two Pound coin (QE II)(Trevithick's Locomotive Penydarren)(Proof piedfort in silver FDC), uncirculated and in absolute mint condition could fetch up to £50 GBP.
A British 2004 Two Pound coin (QE II)(Trevithick's Locomotive Penydarren)(Proof in gold FDC), uncirculated and in absolute mint condition could fetch up to £550 GBP.
A reputable coin dealer will be able to give a more accurate valuation.
Such a coin does not exist. The British One Pound coin was first issued in 1983.
There was no 1811 British Sovereign or One Pound coin minted.
There was no British 1901 Two Pound or Double Sovereign coin produced.
There were no British Two Pound coins minted from 1888 to 1892 inclusive.
There was no 1977 British One Pound coin minted. The first general circulation One Pound coins was minted in 1983.
There was no 1891 British Two Pound coin issued.
Therre were no 1821 British Double Sovereign or Two Pound coins minted.
There was no 1886 British Two Pound coin minted. During the reign of Queen Victoria, they were only minted in 1887 and 1893.
The first gold Fifty Pound coin issued by the Royal Mint was in 1987.
The Pound or Sovereign was not introduced into the British system of currency until 1817 when it replaced the Guinea, and the first Two Pound coin (Double Sovereigns) was minted in 1820.
The Royal Mint produced no British Five Pound coins from 1938 to 1979 inclusive.
There were 20 shillings in one pound. It was replaced by the 5p coin.