Not quite what you wanted, but the Lone Wolf ones are (legally) available online [1]. You may be able to read the downloads, or even the online play versions, with Dutch translations.
if you dont get an answer, well, with all the page flipping and dictionary work already required, adding google lens on top of the process should not be a huge deal. these books basically taught me research skills without me even knowing. it's valuable to learn to ingest information in other languages and we can do so today in a way we could not do 40 years ago.
I already have a few from the library - one title for each series:
* Marcel Groenewege: Schaduwkraai
* Jack Heath - 300 minuten
* Tim Collins - Verraders in de ruimte
* Dustin Brady, Het geheim van spookeiland.