First U.S. Printing: August 1969 [Cover by Bob Pepper; Intro by Lin Carter]
First U.S. Printing: November 1969 [Cover by Robert Pepper; Intro by Lin Carter]
First U.S. Printing: February 1970 [Cover by Frank C. Pape, illuminated by Donna
Violetti; Intro by Lin Carter]
First Printing: March 1971 [Cover by Bob Pepper; Intro by Lin Carter]
First Printing: September 1971 [Cover by Brian Froud; Intro by Lin Carter]
First Printing: March 1972 [Cover by Brian Froude [sic]; Intro by Lin Carter]
Five of the six Cabell titles had Canadian printings in the 1970-72 era. The Canadian printings are undated, but details for a few titles are known: the second, Figures of Earth (printed in Canada in April 1970, five months after the U.S. printing in November 1969) and the sixth, Domnei (printed in Canada in April 1972, one month after the U.S. printing in March 1972). Other Canadian printings observed include The High Place, Something About Eve, and The Cream of the Jest. The only Cabell title without a confirmed early Canadian printing is the first, The Silver Stallion. All six Cabell titles were reprinted in the U.S. by Ballantine / Del Rey in 1979. These 1979 reprints were also issued in Canadian printings. The Canadian printings for both the 1970-72 era and 1979 reprints are distinguishable from the U.S. ones only by a "Printed in Canada" slug replacing the "Printed in the United States" on the copyright page.
Only one of the six had a U.K. Pan/Ballantine edition, and that was The Cream of the Jest (published by Pan/Ballantine on 7th April 1972, seven months after the U.S. printing). (Notice the Commonwealth prices added to the lower rear cover, as depicted above.) Why was only one BAF Cabell published in the U.K.? Probably because Tandem got to them first, for they released three Cabell mass market paperbacks in the U.K. in April 1971, all having introductions by James Blish.The three titles were The Silver Stallion, Figures of Earth, and Jurgen.
The Silver Stallion: The James Branch Cabell Website, which is a fine site I recommend visiting and bookmarking.
And a thanks to Trevor Livelton for the information on Canadian printings.