Venta del Pozzo medal for 23rd Oct.1812

[Allan J Woodliffe]

I have a keen interest in the history and medals awarded to the King's German Legion, and am hoping that someone can tell me about the Venta del Pozo medal. 

As far as I know, the medal commemorating the rearguard defence on 23rd October 1812, was awarded to surviving members of the KGL who took part in the action on the 50th anniversary, 23rd October 1862. My own researches indicate that a bronze medal was given to rank and file, while a silver medal was awarded to officers.

Can anyone tell me any more about this medal please? Are the facts above correct, and is it a scarce medal to find?

Allan