It's already on WoT, but it's so magnificent I can't resist presenting it here also.
At 31.8 mm, it is larger than a contemporary British penny (30.8 mm), but it is thinner, resulting in a weight of 7.0 gram, while the pennies came in at 9.45 gram. The design is totally different making it look like a penny and yet feel different.
The Yorkshire Woollen District Electric Tramways was part of British Electric Tramways (BET), an institution, once the largest operator of tramways on the British Isles, now receding in history.
I am not sure that WOLLEN is a spelling error, though it may be. There are close connections between Dutch and Lowland dialects. Since wollen is the correct spelling in Dutch, it may have been correct in a Yorkshire dialect also.
Peter