Not sure if it could interest you Alec, but when I saw abebooks sharing the following, I immediately thought of you.
They are not signed though


"These were first official Lord of the Rings paperbacks to be published in the US. Ballantine printed them in 1965 after Ace had issued an unauthorized paperback edition. These humble softcovers were immensely popular at the time."







2 sets seems available : https://www.abebooks.com/book-search...j-r-r-tolkien/