Hi Pamela, in 1915 the British were facing a shell shortage and set up the Ministry of Munitions. This not only controlled over 200 British munition companies but also got shells from all over the Commonwealth and strange places like Switzerland, and not forgetting the USA. Some factories exploded, some started producing other chemicals but most just closed after WW2 when the demand fell away. I feel sure that if there was a list of the producers it would have been kept secret as it's not the sort of thing you would like the enemy to know. Sorry we cannot be of more assistance but if anything comes to light I will let you know. All the best, ken.