Suitable sources are:

* OS Local (no use it has Greenwood Avenue)
* NSUL which shows exactly which properties have which postcodes. This shows that the addresses on this cul-de-sac share a postcode with houses on Lansbury Road: a very strong indicator that this is the road name.
* Companies House Open Data: no help as only one property listed at #45 Lansbury Road, so can't confirm the house numbers.
* Raw UPRNs: for pre-2000 properties UPRNs are often assigned in the same sequence as house numbers. This is the case here.
NROSH Open Data: not maintained since 2011, but can potentially be matched with missing land registry parcels (council owned social housing will not be registered). These were clearly built as social housing (as was most of the village). This is helpful as it shows that 81 Lansbury Road with the correct postcode exists.

Most of these require access to the data via downloads, but uprn.uk does show some data from open data. Some knowledge is needed to interpret it: see https://uprn.uk/usrn/26805604.

Accordingly, I've changed the road name, and assigned house numbers to the cul-de-sac with the correct post code.