Fancy a try at cryptography?

Here's an historical puzzle:

CAN YOU CRACK THE PIGEON'S CODE?

A coded message found attached to the remains of a hero D-Day carrier pigeon may never be cracked, British top codebreakers have admitted.

Hand-written on a small sheet of paper headed "Pigeon Service," the message was found in a red cylinder still attached to the bird's leg bone.

The pigeon's skeleton emerged in 1982 from the chimney of 17th-century home in Bletchingley, Surrey, when the home's current owner David Martin decided to restore the fireplace.

The code is transcribed in the article's text and what elements are known are mentioned. Have at it!