There is an old, out of copyright OS map available as a TMS (can be added to JOSM or iD) from the National Library of Scotland (NLS). It has housenumbers on it for houses oresent present in the 1940s/50s for London and a lot of the south east. It is completely accurate in my part of east London. But it is NOT available for OSM use until the end of 2022, which is a pity. But check back in two years!

There is an old, out of copyright OS map available as a TMS (can be added to JOSM or iD) from the National Library of Scotland (NLS). It has housenumbers on it for houses oresent in the 1940s/50s for London and a lot of the south east. It is completely accurate in my part of east London. But it is NOT available for OSM use until the end of 2022, which is a pity. But check back in two years!