Please see my previous reply reference the Sell family. Nothing now remains of the 1880 Cole Green Farm save a somewhat dilapidated wooden shed which still contains a large bread oven. The old farm buildings went in the 1960`s.On checking the 1880 map I see that there was another house , about where the present (1905) house stands. This is in addition to the one demolished in the 1960`s. The Sells might have lived in either of these or in Meesden Corner Cottage nearby where the last Sell in Brent Pelham lived.
As regards a smallholding this is entirely possible but our records are mostly in the County Records Office in Hertford. Have you tried There? They are said to be very helpful.
There used to be an area just up the road from Cole Green, say 10 acres known as " Village Potatoe Ground" and more recently "Old Allotments" now part of Home Field. Could this be part of the smallholding?