I have a pb of Ruey that shows all the CS books and the ones actually in print are shown in bold. (This would have really annoyed me as a kid, knowing that the books were out there but that there was no way of getting them).
Nearly all the books are in print with the exception of the war ones. Why??? These are some of my favourites. I get that in the immediate post-war period it wouldn't hold the same fascination and people maybe even wouldn't want to dwell on it too much, but the pb is from the 80s at the earliest, surely by then the war books should have been rehabilitated?
My "white spine" Ruey doesn't show the same list and dates from 1984. The "War" books were printed in 1988/1989
They weren't the last of the books to appear in Armada. There's a tranche of the "Island" books, the later Swiss books plus the "holiday" books that all appeared later than the "War" books. Perhaps it was felt that the "exotic" locations of Austria and Switzerland were more likely to interest the target audience than Wales.
(And the "bold" on the list didn't indicate what was in print. It indicated what had appeared in Armada at some point)