Can anyone tell me anything about these phones? I found them and they look interesting but I would like to know some info about them. I haven't been able to listen to them yet because I don't have an adapter. I'm pretty sure they're either a DT100 or DT150 but I'm not sure which. They aren't labeled and say only "Made in Germany" "2 x 25 Ohm" and "WK 1007". Also, as you can see, the jack looks kind of corroded, is it worth replacing it?
Sorry for the crappy pictures, it's from a cell phone camera.