Dead author, old manuscripts, live issues: a reader writes

This weblog has received an inquiry from a perplexed person who is trying to establish the legal status of some old manuscripts in respect of which some curiously complex problems arise  There are two questions here:

"(1) My first question relates to the statement in the British Library's Help for Researchers: Manuscripts Collections: Copyright guidance that 

"Manuscripts with an author, created and published before 1989, but after the author's death, remain in copyright until the year published + 50 years".

Given a situation where an author died (say) in 1900, leaving unpublished letters, the copyright of which is now owned by his/her literary estate, does this mean that if a third party published the text of or an image of one of these letters in (say) 1905, but was not given permission to publish the document by the literary estate, could that publisher really claim copyright of the text of the letter for 50 years from the time of publication? If so, then the copyright (in this example) will now have expired, so is the text of the letter now public domain?

A slightly different example:- Given a situation where an author died (say) in 1900, leaving unpublished letters the copyright of which is now owned by his/her literary estate, does this mean that, if a third party published the text of or an image of one of these letters in (say) 1905 and was given permission to publish it, but not own the copyright of it, by the literary estate, could the publisher really claim copyright of the text of the letter for 50 years from the time of publication? If so, then the copyright will have expired, so is the text of the letter now public domain?

It would seem most 'unjust' if a third party could publish a copyright-protected unpublished manuscript without permission and then gain the copyright of it for 50 years, but perhaps this is what the law says!! This could even mean that the original copyright owner is prevented from publishing a work, e.g. if an unpublished manuscript was published in 1988, it would be copyright of the publisher until 2038.

I have searched the Web for an answer to this, but to no avail. It is important for the collection I have in mind, where the author's letters were published after his death - and some of these were even published several times by some well-known recipients of them.

(2) The following guidance cited on the same website seems to suggest that no-one would own the copyright of an unpublished copyright-protected work by the author whose manuscripts I'm holding and which was published after 1989: 

"Manuscripts with an author who died before 1989 but which were published after 1989 remain in copyright until the end of the year in which the author died + 70 years".

Does this mean that my author's copyright of a work would expire as soon as the work was published (he died in 1913)? Would the publisher have any copyright of the work (apart from the typographical arrangement of it), or does the work immediately become public domain on publication? If there is still copyright associated with the work, could it be retained by the Literary Estate of the author if the Estate stipulated that publication of a work was only on the condition that the copyright was owned by the Literary Estate?

Given the above I am not sure how to proceed - any ideas would be very welcome".

Well, readers, here's a challenge for you! Please feel free to post your guidance below, and/or email it to Annette here.