This really is a fantastic piece of art and history.
The Alan Turing centenary cover with Turing Bombe stamp and cancel.
It has been signed by people who played important roles at Bletchley Park during the second world war.
Jerry Roberts cracked Hitler's personal codes.
Asa Briggs the historian was a code breaker at Bletchley Park
Jean Valentine was a Turing bombe operator and now a Bletchley Park Tour Guide
A not to be missed item for any collection as such a rare combination of signatures.