Also, I did have a go at riding it, and, yikes, that would need a lot of practice. It actually felt more unsettling than the trick bicycle with backwards steering that I tried to ride in Dublin (pay a couple of euros to try riding, win 10 euros if you can cycle across the line about 3 yards away... nobody manages more than about 2 feet) -- everything seemed to pivot in the wrong places, and I felt like I was going to fall off any minute. Terrifying!
So, no, I won't be bidding on it, but it was interesting to have a (very brief) go at riding it. I think I will try to get to Cambridge at some point & talk to the Hope St bike folk (and say hello to all you nice people in Cambridge!) but that probably won't be for another month at least.
Thanks again to everyone who offered advice!