Ste,
I agree there is not much in it when you read the descriptions given out by the EA but the main points to look for are the size difference between Turks and English (Turks are generally a lot biggger) and also the claws, English have claws that look in proportion to their body but Turks have the really long, narrow claws that are also often a different shade to the body (lighter), the claws on an English are the same colour as the body. I have caugh signals in black, brown red and bright blue, the colours the EA give can be a bit misleading as it depends on the colour of the habitat