Agreed .. it did cross my mind at the time of adding it, that it was a little out of tune for W.K. to use a title like that!
I think that "W. K., B." is William Kernahan, Belfast.
Some hints:
- A certain "W.K., Belfast." is mentioned in Things New and Old 12 (1869), p. 24 as putting a question.
- "A Voice to the Faithful" 26 (1892), p. 380 also gives "W. K., B." as author.
- A printed Letter of J. A. Trench about the Split re. Raven says "Copies of this Paper may be obtained from W. K., 17 Arthur Square, Belfast." (see here: https://www.stempublishing.com/authors/trench/fer.html )
- The Depot of this "W. K." in Belfast was older: In December 1875 in "Words of Truth", vol. II, sec. ed. books were advertised to be had at "Belfast: Tract Depot, 17 Arthur Square". It is also on the title page of Dr. Mackern's "The Basket" (1874). (I also found "Tract Depot, 13 Arthur Square" and "6 Arthur Square" as addresses)
- In "The Bible Treasury" 11 (1876), page 160 and later (also in vol. 12) one source to get the magazine is "KERNAHAN, Arthur Square, Belfast"
- "W. Kernahan" was the receiver of a letter of J. N. Darby, printed in Letters, vol. 3, p. 64 (February 5th, 1880).
According to https://www.myheritage.de/names/william_kernahan there was a
William Kernahan in Belfast, who died in 1925 (80 Years old). This is probably the right Kernahan, because he had a son with the full name "James Butler Stoney Kernahan" (!)
His grave is perhaps here: https://de.findagrave.com/memorial/186965329
Martin