Cloffe, well done!
You reminded me of something I had read (and archived) in an AyA catalogue:
In 1995, the Spanish proof house implemented a new system of serial numbers.
Now, each gun has a serial number that consists of four sets of digits, separated by a hyphen. Each set of digits has a distinct meaning.
The first is the gunmaker code. The second set designates the type of firearm*. The third set, which may run to three or even four digits, is the chronological number assigned by the gunmaker in a given year, and the fourth set of two digits shows the year of manufacture.
(The codes from 1995 onward were assigned but never used)
* Although it says firearm it should say weapon, because the codes include bows (08) and crossbows (09). The list assigns 03 specifically to "escopeta", shotgun.
JC
