Your gun was made 1995 or after if it has this info code.
57-03-26x-xx
Example in the below site
Since 1995 Spain integrated the manufacturing year in the serial number in the following form:
16-03-001-95
16 = Manufacturer in this case AYA
03 = type of weapon
001 = serial number by the manufacturer
95 = 1995, year of manufacturing
Have you reviewed the proof dates?
https://www.shotguns.se/html/spain.htmlAlso below is good reading
https://www.shotgunworld.com/threads/help-identify-model-and-year-of-arrieta.364056/Mike