Darnity, thank you so much for those links. I've spent the last half hour or so going through the 1921 sale catalogue and map on the Soulbury site, and it's been massively helpful. The Leighton Buzzard one might be able to help me to locate where exactly on Wing Road my lot were in 1911, as their house only has a name, not a number, in that year's census. I suspect that the house numbers along that road may have changed over the years, too, as they don't seem to follow a logical sequence on Google Street View.