Hi, so I have learnt that Henry is my Great Grandfather x2 also. I have found a lot of information about Turnpikes and a Toll Gate at the Gun Inn in documents from the Battle and District Historical Society freely available via Google. Those docs make reference to Netherfield Toll but did not state it's location. So I asked BDHS, they kindly provided a map (I am unable to upload) and informed me:
"The Toll appears to have been situated on the Netherfield Road between Eatenden Lane and Netherfield Way. The arrow shows the approximate position on a modern map taken from information on the 1813 Ordnance Survey map, which marks the Toll. It seems to be about where a house named Sky View is now".