At the time, when I watched Monty Python I found about 25% of it funny. It was only weeks later when I was in a shop trying to buy something that I realised the humour of the cheese shop sketch. Ther sketches were similar to that. This one took a few decades:- www.youtube.com/watch?v=Dgp9MPLEAqA
If you want to put one of these in a parking meter in London then you need to use the slot round the back.