I have been searching for the Magura HS-77, a hydraulic rim brake that has been out of production for the past few years. From what I understand, these brakes were popular on some recumbents of the time as it allowed complex brake cable routing without having to worry about an inner cable being snagged against sharp angles.
If anyone has an HS-77 that is just sitting used in your part bin, please let me know. I'll take them off your hands and you'll get some cash for your trouble.