Detailed Firearms

I've got this Benelli SL121. Beautiful original condition. When I bought it, without seeing it in person, I had planned on refinishing the stock and Cerakoting the receiver, since they showed wear. But I got it and it's just so honest in its age and wear, I'm going to keep it like it is. But I cannot figure out WHAT it is. It is definitely a Spanish made piece -- the barrel, upper receiver, and lower receiver all are either marked Espana or have Eibar proof marks. The part that I can't make sense of is trying to date the unit. The only type of date code I can find is on the barrel markings where I think there is a "D*2," which would be an Eibar proof mark indicating 1984. But from anything I've found, the SL121 wasn't made after the introduction of the SL80. Can any experts weigh in here?