Got my first fire alarm. Federal signal vibratone 450

On sunday, I picked up a federal signal vibratone 450 series A-1. How old is this thing? Will post pictures tomorrow or later today. I got yhus horn fo FREE from my church. Guessing it is building original. Building was built in the 60s. Apperance wise it is pretty dirty, got paint and dirt/dust on it. Who ever painted didnt cover up the alarm before they painted there are splotches of white paint along the sides. This my first fire alarm EVER. Its 12volt DC.