The number 57 has been significant in the Discworld novels- or has it? Here is the list of cameos so far: In Equal Rites, when Esk confronts a hassled trader counting bales of tobacco, he says "fiftysevenfiftysevenfistysevenwell?" before speaking to her. Queen Grimnir the Impaler of Lancre was Queen for 1514-1553, 1553-1557, 1557-1562, 1562-1567 and 1568-1573. There is an Ankh-Moropork law called the "Public Order Act of 1457." A Holy Wood film is called "Golde Diggers of 1457". B'hrian Bloodaxe killed 57 trolls with his battle bread. In Ankh-Morpork, there is a place called Five-and-Seven Yard. Author Felicity Beedle has written 57 books. The hermit, Stump, has been herming for 57 years. There are 57 varieties of Swamp Dragon. The Librarian has compiled a list of strange things, of which there are 57. In Hogfather, something is said to have a weight of 17,857 Tonnes. Does anyone else have any others?
Terry And family lived in Somerset for short time, having moved there in 1957. It may be a nod, the 57 I mean, to Heinz beans, a British favourite, with its fictitious 57 varieties?
Heinz is a company here, too, that has used the fact that at one point it had 57 varieties of food products, I am willing to bet they have more than that now, they make the most popular ketchup, a steak sauce called Heinz 57, and the company owns lots of others , they buy and sell each other so often I don't know which is which, the company I work for is an arch rival, it makes the second most popular ketchup.
Heinz never actually had 57 varieties, it was just an advertising gimmick at the time that they've stuck with on their labeling. There are many thousands of products now. Still, the Discworld 57 is obviously connected with this one.