Thanks for the information and pictures. The Germans do love gearboxes, and so do I. Looks like they have come up with some good ones for bikes and trikes. But there is the retrofit problem unless it is a hub drive.
May Nuvinci prosper, and I believe they are. They make a fine device, easy to retrofit. I guess so, anyway, I haven't tried it. The disadvantage for a bike is the extra weight away from the center of rotation. Is that a bicycle term? I suppose it is not fixed, because the rider moves around a little, but it must be somewhere near the crank. This is probably negligible in a trike.
The range of the Nuvinci is not large, but apparently good enough for the majority of bike owners. I don't have any problems with the 24 speed chain/derailleur drive on my commuter bike, so am not looking to change it. I am just interested in developments. If I ever decide to take a long trip, your trikes look good.