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.html

Also below is good reading

https://www.shotgunworld.com/threads/help-identify-model-and-year-of-arrieta.364056/

Mike

Last edited by skeettx; 01/04/22 10:06 PM.
USAF RET 1971-95 [Linked Image from jpgbox.com]