I don't know anything about Bersa's, but the Bersa 380 plus is a double stack, any Bersa double stack magazine should work with your pistol. I don't see why you need to date the pistol if you just want to purchase a 15 round double stack magazine for it. The pistol was made after 1995. I would assume the pistol was purchased during the Clinton 10 round magazine limit era. Its the ribs in the magazine itself that limits the capacity to ten rounds nothing to do with the pistol. So 15 round double stack magazines should work in your Bersa 380 Plus regardless when it was manufactured. I would contact Bersa about the date of manufacture if you need that info.