That's probably a motion picture film stock -- you may notice the perforations are a different shape than you're used to for 35 mm still camera films (though the film usually will still work in most still cameras). It doesn't seem to follow the naming convention of other older ORWO/Efke films, however, of using the DIN speed number (DIN 54 would be ISO 200,000, which would fog from cosmic ray exposure before it could be packaged). I'd have to suggest, since you have a bunch of it, that you'll have to simply test it to get a film speed and development time. Bracket from EI 16 to about 200, and start with the same development as Tri-X, and by the time you've shot 3-4 short rolls you should have it dialed in (assuming it's not a silver antihalation layer, or so badly fogged from age as to be unusable).
Oh, it might also be microfilm -- are you certain it's perforated? If unperfed, microfilm is the most likely original application, and it'll be ISO 6 to 25 equivalent and require a low-contrast developer like POTA, or extreme dilution of Rodinal/R-09 or similar to get continuous tone pictorial negatives.
