In the end, I didn't got for either the PlusBus or Kangaroo ticket; I just bought a One Day tram only ticket for £4 from the ticket machine at the Nottingham (railway) Station tram stop.
That got me to successfully to Clifton South and back, but when heading off to "do" the Toton Lane route, I only got two stops (NG2) before the tram came to a stand and lost power. That was about 14.00. According to the driver there had been a complete power failure from there to Toton. Nothing moved in either direction. We were asked to get off and stand on the platform; luckily it wasn't raining. I waited nearly half an hour, and of course nobody could say when things would resume - it being one of those "how long is a piece of string?" type questions. So I reluctantly gave up on the idea, walked back to the railway station, and got the train the 3.5 hours back via London to Oxfordshire.
An interesting day, but only a partial success when it came to the track bashing!
As a matter of interest does anybody know when things started to run again?