https://www.metcalfemodels.com/
Quote from their website:
Metcalfe Models & Toys Ltd is a first choice brand for many model railway enthusiasts. From the very first brainwave right up to the present, the company has gone from strength to strength producing card kits to a quality that has never been compromised. You will now see Metcalfe kits in their bright green packaging on the shelves of almost every model and hobby shop nationwide.