Åhlen & åkerlund & Albert Bonnier did publish 3 books in 1942, 44 & 46. These are among the oldest books in the Prince Valiant market.
These books are sometimes called "Jul album".
People in Sweden say that the first book can be sold for 700 Euro's, and the second and third for 320 and 166 Euro's!
However, on Internet auction sites you can buy these books for around 200 Euro's.