Here's something rather different for the penny collectors. The attached photos show a penny sized brass 'coin', clearly marked GPO Telephone Service. This was used by engineers in the pre-decimal era to test the operation of the Coin and Fee Checking Equipment in a public phone box - for those of a certain age the Press button A then button B type phone box. The idea was that the engineer checking the operation of a box should have no access to the money, but needed to test the equipment functioned correctly. He was issued with these tokens which are of the correct size and weight to operate the mechanism, thus avoiding any need for him to use actual pennies. The boxes were emptied by a specialist team and the coin compartments were taken away for the cash to be to be counted. Any brass tokens were removed and returned to the engineers for use another time. In this way any possibility of fraud or theft was eliminated.
The face with GPO Telephone Service is plainly obvious. The reverse shows S Eastern District, which refers to the organisational structure of the GPO at the time, and the number 447, is likely to be the identifier for a specific engineer involved in this work. Alternatively, it may simply refer to the actual number of the token itself. To the best of my knowledge it isn't clear which. This particular example came from Margate exchange, some 30 years ago. End of history lesson!