Anyone got a shilling?

Most definitely! Couldn't pass a phone box without pressing the buttons in the hope that some coins might fall out. You could do a lot with tuppence then.

I never did that with telephones but I did with the seven bridge tolls

I did the press button B to see if you got any coins back, also as a teenager in the 70’s I learned how to make free phone calls from the public phone by tapping it. I used call my friends or girlfriends from the phone box for free so I could talk without my parents hearing me.