Thanks Dairwin – I was hoping there might be some way to narrow it down a bit and a high ground Lancaster crash site has been cited as the possible source.

Bruce – Thanks for the id – most interesting, though not what I was expecting!

The elderly chap who recovered these some 30+ years ago is still with us, but his memory is failing badly – his son is hoping that if I can identify the parts, perhaps even narrowing it down to which actual crash sites he visited years ago, it might help him reminisce, which would be good therapy for him.