Hello Permeke,
you probably have a Swedish Broadcast module, not to familiar with them, but Danner Berlin made the cassette type enclosures for the german 21inch DIN racks. They sold them as kits to companies like EAB, Telefunken, the historic TAB and Maihak, only Siemens made their own housings, but the parts interchange with the Danner modules.
Due to the fact that the german broadcast technologies were exported all over the world, AEG-Telefunken was the largest manufacture of radio transmitters, they also furnished the studio gear, you find those cassettes from Argentina to Obervolta.
If radio stations needed to customize their equipment, they bought the empty Danner modules and build stuff from scratch. Most famous the EMI Carl Lindstroem V76 units that are only related to the classic V76 circuit but have an entire sound of their own...
While living in Seattle I bought an entire rack of Danner modules that were used to house the control electronics for an EMD machine.....
So there are many chances you can find those DIN modules used by other audio companies...
Hope that helps your questions, if any of our Swedish readers have some hints, info or pics, please feel free to share...