Now that call box cover REALLY brings back memories. In the days before cell phones and portable radios, unless you were in a patrol car, that call box was your link to dispatch.
If you arrested someone, you walked him to a call box and called for a car to take you in to the precinct station.
In response to the earlier question re: what caliber you could carry. During the short time I was on the force (1961 - 1963) you had to carry a revolver of .38Spl or larger. You were issued a Colt or S&W .38Spl and had to buy anything else. One of the guys who graduated in my class showed up the first day with a .357 Python. If you carried anything other than a .38Spl, you had to carry at least 6 .38Spl rounds as "Buddy loads" for your partner. I carried a .44-40 Colt New Service that I got in a trade with my uncle. It was badly polished and re-nickeled but shot really well and was previously owned by the Sheriff of Jackson County, MI.