By way of a somewhat belated update. I am a direct descendant of the original owner of "Toomers", ie before it passed to the Grant family. After Roy posted his original comment on this thread back in May 2013, I solved the mystery by consulting the Enclosures Map at the Wiltshire Archives. The Key to the plot numbers was included on the map itself, and it showed two plots under the heading of "Toomers Copyhold", but with George Grant's name written underneath: one allotment (plot 51) and one inclosure (plot 140) containing a dwelling. I then looked at the Tithe Map (signed/certified on 11 Jan 1841, a few days before the Great Flood) and immediately noticed that whilst the plots themselves were identical to those on the Enclosures Map, so instantly recognisable, the plot numbers were different. Plot 140 (Toomers) had been renumbered as Plot 147, and was owned and occupied by John Grant. Looking at later maps, a lot of the plots were still clearly identical, but yet again had different numbers - and this is what had caused all the confusion.
"Toomers" stood at the end of a narrow lane leading west from the old school on New Road/Church Rd. There was a row of five cottages on the left (just after the lane on the right to Manor Cottage) and Toomers stood on the opposite side, immediately after the last one. I have a photo of these five cottages, taken from the 1916 sale particulars of Manor Farm, but I don't know when they were demolished. They appear to have made way for New Road to be extended. Using the NLS Maps overlay facility, the Toomers dwelling house would have been in the front garden of 7 Meadow View, New Rd, although the plot itself would have included the field at the back where the sewage tank is located! there was no sign of the Toomer dwelling in 1877, according to the 1:250000 OS map surveyed in 1877.
