Why workshop?

[abu nuwas]

There survives a manuscript draft of Wilfred Owen's 'Anthem for doomed youth' with amendments by Siegfied Sassoon- I have a book containing a facsimile of it - the original is , I think, in the Brtish Museum. As far as I am aware, the poem is attributed solely to Owen.

IMO there is a difference between someone completely rewriting a poem and suggesting amendments and alterations whch may or may not be implemented verbatim.

unless they had permission that could only happen today if it were out of copyright or if they had permission. (i'm pretty sure.) so the manusript would have to be 70 years older than the dead person
or in a non member of the Bern treaty

I obtained copies of various unpublished papers from the Archivist at Brooke's college, which actually belong to the estate, after signing my life away that I would not reproduce. Not actually a copyright thing, though.