Our hero is called Prinssi Peloton by this publisher from Finland. They did print at least 2 books:

These are Max Trell with the b&w illustrations by Hal Foster similar to Hastings house edition. It's also a softcover reprint of the ‘Otava, 1955’ and 'Otava 1971' edition. Price estimation 10 euros.

Book 1. Prinssi Peloton : tarina kuningas Arthurin ajoilta; JAL 1987
Book 2. Prinssi Peloton : taistelu hunneja vastaan; JAL 1988

Book 1

Book 2