Hello Dan,
You continue this thread with some black and white covers, I'll go along with you.
Here are several covers of Biggles' stories. These booklets were published in a limited edition. In the Netherlands not all the stories of Biggles were translated and published in books. The International Biggles Association published each of those "missing adventures" in booklets. The interesting thing is that the booklet contains the story in English and in Dutch.
See the example of
Biggles takes the bait. One side is English; turn the booklet around and you can read the story in Dutch.
All the covers are from
Peter van Stigt.
Jos