Bugger, yes, I did. Apologies.
OK, how can I reverse this lot out?
(I think there's also another smaller changeset in the same area which will need reversing out too - I'll have to check back.)

Apologies, wrong source. Actual source was county council online definitive map at http://my.cambridgeshire.gov.uk/myCambridgeshire.aspx?MapSource=CCC/AllMaps&Layers=row,row-tab=maps