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.