Tim,

I found a website authored by AW's great-great-nephew Ian Williams, who says

"I live on a piece of land that my family have owned for over 250 years. The land also belonged to my great great uncle ALFRED WILLIAMS who was a well known swindon/wilts/oxon area poet and author [1877-1935]".

His contact details (including full postal address) are posted on the site. He should be able to help you find out more about the Williams' property.