The casing used to be a small ikea desktop organiser thingy which i didn't need anymore. It is quite cheap wood, so if i ever do a project like this, i will not be cheap and invest in nice wood (if i have proper tools by then). 
It is basically a multiplex faceplate, with holes for the speakers, buttons and screen, which i painted with a paint-mask make out of scotch tape. 

After painting i glued the faceplate into the sides, into the already existing grooves. (Thanks ikea.) 

After that it was just a matter of lots of linseed oil, which, on a sidenode, i found in a glass bottle with a cork in my parents place, and i think it is over fourty years old.