You mixed up manufacturers:
-) there is Braun in Nürnberg, with that achromat as logo, with a long tradition in optics and cameras since 1915. They made the Paximat projectors with their propriatory trays. Later they changed to trays/magazines of competitors as hinted at in the name
Multimag.
-) there is Braun in Frankfurt, with that electronic tube in their logo. They started with audio products and got famous for their design. Only in the 50s they entered the photo field by manufacturing electronic flashes and later bought up camera manufacturer Nizo.
Your projector is from this Braun manufacturer.
Yours takes the
Universal-tray, also called
Gemeinschafts-tray, nowadays the most common tray.
http://diawechsel.de/files/2014/2831/3786/magazin_uni-2.jpg
For West-Germany alone I counted so far 10 basically different magazines, plus subversions.