Wm. Collins Sons & Co. Canada Ltd was inconsistent in the way it handled reprints for the White Circle paperback imprint. Usually the reprint is indicated on the copyright page. Sometimes that is missing but new covers or new numbering in the series were used. Once in while there are more subtle differences between copies that might indicate reprints but nothing on the copyright page or anywhere else in the text block to confirm as a reprint.
Dyson Carter's Night of Flame is seen with two cover variants. The more common has a black irregular dot on the "G". It also has a green tint missing from the less common cover. This is most obvious on the bottom of the man's ear and in the shadows under the woman's arm. There is nothing else different about the books.
The Commandos by Elliott Arnold was first published by Collins in 1943 and again in 1945 with a different cover and series number. This version was reprinted in 1946 and indicated as such on the copyright page. There is a clear difference in the covers of the two printings. There is also a variance within the 1945 printing with one copy having a darker blue/green background which makes the black text hard to read.
White Circle 256 - 1946 with dot
White Circle 256 without dot
White Circle 256 back