Need some assistance in determining date of this 1100

[jasonconnellee]

Good morning all. Recently I picked up a 20 ga. 1100. Trying to determine age of gun. Would like to find a barrel for it. Currently it has a fixed skeet choked barrel. I am having some difficulty understanding the date charts that I have been reading. I was hoping someone could chime in and take a look at the photos I have attached to this post and help me date this gun. Thanks is advance.