My 6X gt-grandfather, John Wall was the miller at Chamberhouse in the mid 18th century. There is a lease with George Amyand dated 1758 signed by John. He appears to have given up the mill in 1765, the new miller being a John Marshall. George Amyand bought the Chamberhouse estate in 1758 so it is possible that John Wall was the existing tenant under the previous owner, John Lansdell. You probably know the mill still exists as a private house.