I did a little more searching and discovered that "21" is the Ferlach manufacturer code for Fanzoj. Apparently all of the Ferlach gunmakers received a number to identify guns manufactured by them post-1945. The first number, #21, was issued to Fanzoj, the second gunmaker received #22, etc. The number following the dot is the serial number. So it appears that Andrew's gun was the 45th gun manufactured by Fanzoj after being issued the 1945 code and mine was 2,000+ made in 2008. All in all a relatively small output!

Owen