This is the Cocoa and Chocolate Works at Luton, opened in 1902. Imagine if there was no chocolate, for eating and drinking. This could happen without Fairtrade, for in many cases the Fairtrade Premium they receive on top of the price of their crop that allows them to keep going and fight off the sad facts that cocoa prices are steadily falling, that climate change is affecting the weather and bringing weather related crop diseases, and that the trees which give the cocoa are now in much need of replacing due to their advanced age.
Now for the answer to our teaser, as this set is listed as a set of 28, apart from, dare I say it, the spanner in the “works”, which appears in the 1920-40 LCCC handbook (Ha.107 - in the 1950 edition), where it suddenly becomes a set of 29, the additional card being of the "Pickle and Vinegar Works”. However this is not mentioned in our modern tobacco index handbook which says there are only 28 cards. And a quick search through the online auctions also finds sets of only 28 cards.
However my detective work tracked one down in a recent Loddon Auction (7th of Dec 2021) where there was a lot that actually said “Cigarette cards, C.W.S. Co-operative Buildings & Works, 5 cards, Printing Works Longsight Manchester, Leman St London, Weaving Shed Bury, Pickle & Vinegar Works Middleton Junction, & Tea Department London (gd)” and I have had a look at that card (as can you, at the Saleroom. This clearly shows the reverse says “C.W.S. Jam, Pickle, & Vinegar Works, Middleton Junction” – however the front of the card only says “Jam & Marmalade Works”. You can see this much better at the online collection of the New York Public Library