Crypto puzzle

Im a member of an Italian metaldetecting association and we discovered on a world war II scenario (aproximately near Florence) an empty bullet containing a coded message (8-13-1944). Our aim is giving it to the local veteran museum but, despite our struggles, we havent solved it yet. Here is the link to the coded message http://metaldetector.forumfree.it/?t=70205379 Any suggestion or contribution is welcome! :)