A commemorative medal was issued on the instructions of Queen Victoria to those who participated in the Battle - forty three years (43) after the event.
As usual the Antiques Road Show only gets the story partly right! The Naval General Service Medal and the Military General Service Medal were issued in 1848 to all survivors from Military and Naval actions from 1793 onwards (including Trafalgar of course). They count as campaign medals, not commemorative medals. Prior to the NGS and MGS the only campaign medal which had been awarded to all ranks was the Waterloo medal of 1815.
I'm a cold-war warrior too and I certainly dont have any desire to have a medal for it! My own single GSM looks pretty insignificant compared to the chestful wore by some guys (and girls) now but I dont see the need to have any retrospective ones to make up the balance.