Robert Whittaker
Great thanks.

Re the building positions - I think they're actually pretty much correct, at least around Lilley's Alley, and it's the Bing imagery that's mis-aligned.

The Land Registry has released their "index polygons" onder a licence suitable for use in OSM, so we're able to align things to them. (We're not likely to get anything with better alignment.)

The main use is to use them to align aerial imagery (e.g. using obvious hedges, walls and other boundaries) and then align the OSM objects to the imagery. You can add the polygons as a layer in iD and JOSM. See https://osmuk.org/cadastral-parcels/