Once again thank you for your search efforts and the further input.
It was Helen N who put Jim Humphreys in touch with the former Land Girl and the incident featured in her book relating to the two Hoveringham memorials – if you PM me an email address I’ll send you a copy of an article about his visit.
Whilst in the UK he visited his brother’s grave and it is the relatives of the other aircrew that he is trying to contact.
The normal Air Historical Branch and Hendon contacts have been pursued for the Aircraft Accident Card etc.