I had completely forgotten I had asked the question (it WAS 10 years back after all...).
I eventually came to the same conclusion as GUEST who just refreshed the thread. I decided that the scale length was pretty close to half that of my "big" banjo, so reasoned that according to Pythagoras on string length, it ought to go up a full octave. I tuned to the full octave and found that standard gauge strings didn't actually break, but the top string was close to snapping point. I replaced it with a lighter gauge string and it worked fine - sounds beautiful.
It was very useful to have when we managed to travel to The Getaway on our 2005 trip to the USA and Canada as I could take it in the overhead locker on the plane, although it did confuse the x-ray scanner people at the airport.
Quack!
GtD.