I found this Dutch release with one English title that is also the title of the album. The title of the song/album is called ‘The happy Achterhooker’. The Achterhook is a region in the Netherlands so Achterhooker is capitalized even in Dutch. The only confusion left is if I put it like ‘The Happy Achterhooker’ or ‘The happy Achterhooker’.
The song is sung in Dutch, and all of the other songs are also in Dutch ans have Dutch titles.
This is how the titles are written on the back of the cover:
I’m from the Achterhoek myself, and I did indeed assume it was some kind of pun on how an English speaker might pronounce ‘Achterhoeker’ as ‘Achterhooker’.