Hi, Yes I do remember Hayes/Heyes the ice cream people quite well. You are quite right they did sell ice cream over the fence, this was in the entry between Morgan Street and Gaskell Street. All that was required was to shout Mrs. Heyes she would come out of the house and them go into the shed to get your ice cream. The son was called Sammy. I lived in Morgan Street our gate was right opposite.
The Chemical works that you are referring to was located on the right hand side of Fleet Lane going towards Derbyshire Hill on the Parr side of the Railway crossing. (the other side was the railway hotel). I was talking to someone recently about this works. We knew that whatever was made there was secret and had some connection with the WW2 war effort. They apparently didn't employ any local workers, They were transported into the works to maintain the secrecy connected with the work..