Yesterday I was reading a Rudyard Kipling's book, the Just So Stories, and I found this picture in it:
http://www.ibmh.msk.su/vivovoco/VV/E_LESSON/KIPLING.HTM
If you look at the right down corner of the drawing, there is a monogram very similar to Tolkien's. In this case, in the monogram there are the letters R and K (from Rudyard Kipling). This drawning was done at about 1902.
Do you know whether it was usual for English writers at the beginning of the 20th century to desing their own monograms? Until now I thought that only Tolkien designed one, but it seems I was wrong.