Ownership of family ephemera - who has the right to ownership, the family or the purchaser?

I began my research journey for my first book, A Bare Chronicle of Existence - Stories and Letters from internment in Norway during WW1, with a collection of letters in our family archives. Richard Arnold Clarke (known as Arnold) was my husband's grandfather and it was the letters he wrote whilst interned in Norway during the First World War that inspired me to research further and then write the book. At this early point we were aware of a small number of letters being sold on the worldwide philately market. The family had no idea how these letters had escaped from the family collection and, at that point, did not realise how the next six years (to date) how many more we would discover. As I have become more aware of more letters, a question keeps bubbling away in my head - who is the true owner of these items? What would I do if I owned (and potentially paid a lot of money for) items that belonged to another family would I be prepared to hand them over? Online sales platforms are awash with First World War ephemera that collectors bid for but we can't be the only family that are striving to reunite specific items that relate to a family member.

I have had mixed responses regarding things that were written or once belonged Arnold. The best situations have been when the current owner of the object has willingly and enthusiastically passed the item on to me believing that it should be kept with the letters that the family owned. This has happened with individual collectors as well as some sale rooms who when the items did not sell in a bulk lot were happy to extract them from the lot and just hand them over to me. In a couple of instances, I have swapped some of our spare envelopes for letters. Traditionally it was the envelopes (or covers) that were most valuable to philatelists as the stamps and censor markings were rare and of interest. These days it would appear that keeping the letters with the envelopes is the better approach. I am horrified to hear that it was once a practice to destroy the contents of the envelope and just keep the envelope itself.

I have been fortunate, primarily through giving my HMS India talk to philately societies, to now have come connections in the philatelic world and it is thanks to some of these contacts that I have been notified of letters being sold or of specific collectors who have some of the letters in their collections. Most of those I have contacted have happily sent me scans of the letters and allowed me to use them in my writing and social media which has been a wonderful way of continuing Arnold's story and it has filled in some gaps in the families collection. I have also had individual collectors assist in the tracing of letters and in helping me work out how the letters may have come into the open market.

A card I was alerted to by one of the philatelists I had been in contact with. It was being sold on eBay and I was the only bidder and was successful in purchasing it. Unfortunately the seller had got the item in a bulk lot and did not know anything of its provenance.

There is one particular larger item with a collector that I am anxious to get a look at but unfortunately the owner keeps forgetting to pass on the scans he has promised to send. I find this frustrating and it brings me back to me original question - this item was Arnold's and now we, his family, have been in contact with the current custodian after a plea was posted on social media to trace the story of the item. It has been three years since we first made contact and we have not seen anything of the item and I will admit that it makes me a bit cross as the current custodian as an intellectual interest in the item where as we, as a family, have a deep seated connection to the item and a deep desire to see it. Is one of us more entitled than the other? I, perhaps, have an opinion on this but I don't know if it is the right one, if there is such a thing but one thing I am sure of and it is something that I have done and that is if, in my research, I have found any artefact with a connection to a family member am able to contact then I will definitely contact them and make sure that they have had access to that item. I am really hoping that the same courtesy will be offered to me and to the rest of Arnold's descendants.