Our hero is called Prinssi Rohkea by this oldest publisher from Finland. They did print at least 1 book in 1948.
Prinssi Rohkea : jännittäviä seikkailuja maalla ja merellä.(Prince Valiant in the days of king Arthur). Helsinki : Uusi Suomi, 1948
32 pages; 27 cm. Black and white with colour cover. Compiling original pages 343 – 362 and 364 – 375
Uusi Suomi was a newspaper from Finland between 1847 and 1991. The probably had our hero in the newspaper and decided to print an album out of it.
This book is very rare, price estimation between 250 and 400 euros (estimation 2006), cover artist not known.