I ran into him at the place I stopped in for lunch, and my camera was locked in the car. At that time I wasn't navigating very well, as I had an open wound on the ball of my left foot that had gotten infected, and I was still 3 days from home. So, I didn't get any pics, didn't think to get any contact details. Wish I had. I do like what you've done there, with your trailer.
You know, that trailer design is simplicity itself. If I had a welder I could build one in a weekend pretty readily, with a 20" donor bike for the rear triangle. I just don't like an articulated vehicle with power on one side of a flexible joint, and steering on the other. I've thought about a "power trailer" (small 1 - 1.5 KW gas powered generator, a couple deep cell batteries), and electric drive on the bike itself. If they weren't so expensive, I'd like a tadpole recumbent trike with 350 watt wheelmotors as the front wheels, and a wide gear range pedal power system to the rear wheel. Tow the power trailer, have a useful pedal trike when you feel like pedalling.