In a section on Iris Murdoch as a correspondent, her biographer writes
"She always answered rapidly, in her own hand, without secretarial help
('I could not bear a secretary'), on J. R. R. Tolkien's rolltop desk,
which she and John had bought in the 1970s,
apologising when absence delayed her reply . . . " (p. 569)
--IRIS MURDOCH: A LIFE, by Peter J. Conradi 
Now, I knew about the desk at Wheaton, a photo of which appears in THE ANNOTATED HOBBIT (second edition, p. 2) and another of Tolkien himself sitting at it in Pam Chandler's photo collection ("Pamela Chandler Portraits of J. R. R. Tolkien"). But I'd forgotten about the rolltop desk, nor ever wondered what had become of it. Having now seen this reference, I remembered seeing a photo of Tolkien sitting at it as well. After some searching I've now located it in Dr. Blackwelder's pictures-of-Tolkien collection, TOLKIEN PORTRATURE , which includes a poor-quality photocopy of the photo as image #Pl 24 (photograph, right side, #24). Unfortunately, he does not identify the source, other than that the photograph itself dates from 1971. I know that eventually I'll come across the article where this photo appeared, at which time I'll try to remember to post an update giving the source.
Murdoch herself died in 1999 at the age of eighty, after having suffered from dementia for several years (as dramatised in the movie IRIS , which I've not seen). I assume the desk is still owned by her husband, John Bayley; I wonder if he knows what a treasure he has? And where it'll end up.
In any case, a fun little linkage, and reminder that Oxford is, or at least was, a small world with many interconnections, many of them not obvious to an outsider.
*although it turns out that in a tech upgrade since my last visit the library's done away with photocopiers: now you have to scan items in and then hike over to the Allen building to print them out. On the plus side, you can now choose to print or to copy the scan onto a jump drive. Progress? or merely change?