It looks favorable from the obverse, but I would like to see the reverse suspension link which was cut from the photo. It should be thicker and squattier or smaller than later issues.
The s/n is probably original, but there is a small chance the reverse could have been buffed down to add a lower, three-digit number. This could only be determined by observing the piece's thickness.
Jens unfortunately I can't tell from this photo. I would have liked to see a slightly squattier ring, but it may have been elongated from the excessive wear.
Try taking the medal and comparing it to another later issue like 800K - 2M and your earlier medal should be slightly thicker to the later issues.
I have one a three-digit in the 2XXs, but it is unfortunately packed away and I don't have pictures of it for comparison.
