The other interesting fact I know about it is that the reverse design tells you where to get it redeemed ! Eaton's publishing house was based at the Cock and Swine, 74 Newgate Street, sadly long demolished. If you're interested in more about Eaton, there's a lot of academic literature which discusses his activities as his friends and clients were basically a who's-who of the radical political scene of 1790s London.
Here's the front page of Eaton's edition of the Rights of Man, for reference, where he's "Citizen Daniel Isaac Eaton, Printer to the Supreme Majesty of the People".