Hello Simon - we don't record the age of pavements so I would recommend contacting the actual landowner direct to see if they can assist.
If the land/pavement is registered then the register will confirm the legal ownership - you can search online for registered information or we can complete a search of the index map for you as explained in our
online guidance
The alternative is to look at the register for a property adjoining the pathway to see when the builder sold the plot to the first private owner. It won;t give you a precise date for the path's age but it will get you within range for example.
Otherwise it's back to the local authority to see if they have any history re the development of the sites/roads or local knowledge perhaps?