Needing info on this fire extinguisher

My boyfriend and I were exploring old homesteds here in Montana over the weekend. Saw this hanging in the attic of the house which had evidently been vacant for years. Although there were no visable ways to enter the attic from inside the house, he was able to climb on top of the roof and remove a few boards to get in. After our initial look, we assumed it was, maybe an extinguisher, and were looking at the spring aparatus, making it trip the spring and luckly, didn't break the bottle. After reading about some of these items, we're interested in the approximate year this was made and maybe a value. There is no writing what-so-ever on the this but everything is in amazing shape and it looks newer than most I've seen on here. Also, most of what I'm seeing are the throw types. This one looks heat activated. Just curious about a date and value, even though we're not interested to sell. We'd rather enjoy our lucky find and have as a conversation piece. Any information would be of great help.