You can email SigSauer - as they're located in Eckernforde, where your gun was probably made. They should be able to help you with some information. Having emailed them about mine, they were at least able to provide a date of manufacture based on their records. Worth a shot!
h ttp://www.sigsauer.de/index.php?id=1028&lang=en
Also disassemble the gun, look under the barrel lump for any stampings or Proof Marks, as they should also provide some information.