TW I have only ever seen 409 stamped on the berettas I have looked at my 410 has no model no from memory the 409 has "ausonic steel barrels? the 410 titania steel and 411 some ohter type that escapes me at the moment
GWP my gun has 2 triggers just I cropped the photo a bit much
as for choke it has 18.4/17.4 on the left and 18.4/17.6 on the right well that was what it used to be it now has .008" and .015" it was the best thing I ever did to my gun