Danish dixieland jazz band from Svendborg.
Not sure if they are same than Dutch? big band Riverboat Jazzmen active at least in the 1990s. (more information welcome).
1959 line-up: John Knudsen (cornet), Bent Bay Hansen (clarinet), Niels Thrane (piano), Erik Henriksen (banjo), Bjarne Hansen (bass), Bjarne Saaby (drums)