Just to finish up the thread, the local paper today published the rest of the story as related to an historian by ex-members of the home guard. The location matches with what I'd found earlier.
It seems the Hampden came down around 7.30 am (would have been daylight) and was spotted by several locals. It should have been heading for Cottesmore after raiding Dusseldorf - the crew actually thought they were over France.
The Hampden circled and attempted a wheels down landing in a cornfield. The undercarriage was ripped off by a hedgerow and the aircraft carried on into another field.
The navigator had been injured earlier and the pilot suffered a broken arm. The rear (more like a mid upper?) gunner had been hit with machine gun fire and died later in the local hospital.